ATI 3850/3870 Voltmod thread [Archive]

K404

11-22-2007, 12:02 PM

Updated:

Tested by multiple users and the mods work fine.

Mods are carried out at your own risk. I will not take responsibility for any voltmods gone wrong. No-ones forcing you to mod your cards and invalidate your warranties.

http://img119.imageshack.us/img119/8625/3870corecontrolfinalic3.th.jpg (http://img119.imageshack.us/my.php?image=3870corecontrolfinalic3.jpg)

http://img504.imageshack.us/img504/7303/3870gddrcontrolfinalql8.th.jpg (http://img504.imageshack.us/my.php?image=3870gddrcontrolfinalql8.jpg)

RAM mod: 80K or 100K trimmer connected between the points marked in blue. Some cards appear to have slightly higher default voltage. If so, I recommend using the higher value of trimmer (ie...100K).

Thanks to (in no particular order)

Rumon, Miwo, largon, Kyky, pinto, pitya

optional core voltmod points (thanks to Largon)

http://www.xtremesystems.org/forums/attachment.php?attachmentid=68027&d=1196445046

96redformula

11-22-2007, 12:13 PM

Post em up here please!

K

You all should be able to control your voltage through software. You just need some applications to be able to do it in the near future.

hstuehmeyer2000

11-22-2007, 12:16 PM

take a look at this
http://www.overclock.net/ati/261940-3870-volt-mod-bios.html

K404

11-22-2007, 12:35 PM

I've heard that some versions of ATITool arent holding the settings, plus realtime adjustment mid-bench is always welcome.

:) Software voltage adjustment is good, but I'll always go for a hardmod that I can control.

If I had the cards, id be looking for the mods myself, but cant get a hold of either :( May as well hit the ground running when I invest..

nFo

11-23-2007, 12:10 PM

Has the: ATI Radeon 3870 a cold bug ?
I want maybe put a single stage on it. :cord:

So, I removed the stock cooler.

Where I need to look on the PCB ?

K404

11-27-2007, 12:05 PM

Hi. The control ICs are on the back of the card, towards the rear. (opposite end to the monitor plugs)

Sage

11-27-2007, 03:04 PM

cant wait for this to be up and running :)

Cha0s

11-28-2007, 04:14 AM

^^ my card comes tomorrow ;) then i try to make some pictures ;)

nFo

11-28-2007, 05:48 AM

Ok, sorry I'm bussy with it.

I need more day light. ;)

STEvil

11-28-2007, 06:04 AM

volt mod bioses do not work.

kemist

11-28-2007, 07:02 AM

I will be getting one shortly, if no one has posted by then i will put some pics up.

K404

11-28-2007, 08:00 AM

The core uses the uP6201AQ controller- same as whats used on the 2600

For the RAM: the controller is a uP6101BSA. The voltmod, I suspect will be a variable resistor between pins 3 and 6 of this IC, but i dont know what value yet.

Im hunting for more info at the mo.

I cannot confirm or guarantee that anything i say in these posts will work. I suggest no-one tries what I suggest until someone else can confirm it. If I had a card of my own, id try the mods myself first.

close-up pics (taken by Rumon..thanks!):

http://img161.imageshack.us/img161/4599/3870corecontroliczl5.jpg (http://img161.imageshack.us/my.php?image=3870corecontroliczl5.jpg)

http://img161.imageshack.us/img161/9800/3870gddrcontrolictk0.jpg (http://img161.imageshack.us/my.php?image=3870gddrcontrolictk0.jpg)

Also posted in VMod section

STEvil

11-28-2007, 08:31 AM

Carrying this over from the other thread for those who attempt this before more info is acquired, will make it easier ;)

Just for reference, as long as voltage modification points are between ref and ground you can start at a 100k resistor and measure voltage change, then put in a 50k and repeat.. then 25k, 10k, 5k...

When you get one that increases above stock (say from 1.25 to 1.3) then you need to back up one step and thats the best starting point usually.

I use old 3-pin fan connectors to allow fast changing of resistors without having to resolder each one.

K404

11-28-2007, 08:39 AM

LOL I was gonna suggest that, but seems like a cheats way of doing it ;) :D

Hey..whatever works though!

For the core...will need someone with a DMM, and the datasheet to get things moving

pitya

11-28-2007, 11:20 AM

I found something. Maybe useful, maybe not. It's a Sapphire HD 2600XT GDDR4. Original here :http://www.topmods.net/articles/?id=104
--- Autotranslation from Russian ---
"For food GPU chip meets the marks - uP6201AQ VLF74P. This 24-hnogy (dvadtsatichetyrehnogy) stabilizer diet, which is very difficult to solder to resist, because the legs are very small. But if those resolved so, it is one leg podstroechnogo resistor at 80 kOm to solder to to the 13rd leg stabilizer, and another to land. If someone is afraid of losing a guarantee, it is possible to use a pencil method to resistor R650 (nominal value of 2.43 Ohms)."
------------------------------------

nFo

11-28-2007, 12:01 PM

The core uses the uP6201AQ controller- same as whats used on the 2600

For the RAM: the controller is a uP6101BSA. The voltmod, I suspect will be a variable resistor between pins 3 and 6 of this IC, but i dont know what value yet.

Im hunting for more info at the mo.

I cannot confirm or guarantee that anything i say in these posts will work. I suggest no-one tries what I suggest until someone else can confirm it. If I had a card of my own, id try the mods myself first.

close-up pics (taken by Rumon..thanks!):

Also posted in VMod section

Ok thanks, I can't get sharp foto's. :confused2
http://infomb.googlepages.com/RV670.jpg

Timbosan

11-28-2007, 09:56 PM

if that pencil mod is the same i would definitely not try it as the resistance is way too low for a pencil mod (2.43 ohms)

K404

11-29-2007, 05:45 AM

Scroll up- I think the images in post 12 are fine, "all" we need now is the datasheet for the controller

EvilBellyLint

11-29-2007, 07:23 AM

Scroll up- I think the images in post 12 are fine, "all" we need now is the datasheet for the controller

was about to post the same. The images taken by Rumon look
sufficiently clear I think. :)

EBL

Rumon

11-29-2007, 07:58 AM

was about to post the same. The images taken by Rumon look
sufficiently clear I think. :)

EBL

If you do not think the images posted by K404 are clear enough you could always grab the actual file itself you can zoom in a fair bit more without losing any image quality

HD3870 PCB 1200DPI (SendSpace) (http://www.sendspace.com/file/g9xz9i)
HD3870 PCB 1200DPI (RapindShare) (http://rapidshare.com/files/72884225/HD3870_1200DPI.JPG)

been trying to find the data sheet for it but no luck

Miwo

11-29-2007, 08:06 AM

Hey guys,

I've just obtained the datasheet for the uP6201AQ
http://www.rit.edu/~mkw1084/miwo/3870/uP6201AB_DS_03_070829.pdf

:up: :cool:

EvilBellyLint

11-29-2007, 08:32 AM

Hey guys,

I've just obtained the datasheet for the uP6201AQ
http://www.rit.edu/~mkw1084/miwo/3870/uP6201AB_DS_03_070829.pdf

:up: :cool:

awesome

largon

11-29-2007, 11:50 AM

kyky

11-29-2007, 12:02 PM

I made measurement with a numerical voltmetre (I afflict use a Français/Anglais translator)
Vgdr4
http://img441.imageshack.us/img441/2295/3870vddrby4.th.jpg (http://img441.imageshack.us/my.php?image=3870vddrby4.jpg)

Vvpu

http://img529.imageshack.us/img529/3663/3870vcorewn0.th.jpg (http://img529.imageshack.us/my.php?image=3870vcorewn0.jpg)

Sage

11-29-2007, 03:18 PM

1.89v for the RAM and 1.32 GPU.. both sound right to me :)

god damn id love to get an extra 10% into both of them :D

K404

11-29-2007, 04:19 PM

http://img138.imageshack.us/img138/6/3870corecontrolicforresqf8.jpg (http://img138.imageshack.us/my.php?image=3870corecontrolicforresqf8.jpg)

Please can someone measure the resistance between the Feedback pin (marked in blue) and GND?

Rumon

11-29-2007, 06:01 PM

I don't see why the method for modding a HD2600XT referred in post #15 (http://www.xtremesystems.org/forums/showpost.php?p=2588077&postcount=15) wouldn't work as we're dealing with the same controller.
Someone with a DMM please measure resistance between the 13th leg and the middle and far-right spot in this pic:

68008

Ok just to say i have not done any measurements for hell of a long time so wait for verification from someone else if the readings sound about right, but if they are way off then well i suck at taking readings :rofl:

DMM setting = 200
For both points measured against pin #13 on the pic i got
0.3
I done it a couple of times at it hovered on 0.7 but it eventually went to 0.3 both points

Please can someone measure the resistance between the Feedback pin (marked in blue) and GND?

DMM setting = 20k
Also K404 i did a measurement on Pin#13 FB and Pin#4 AGND got a reading of

5.12k

Miwo

11-29-2007, 06:54 PM

I can confirm the same readings as Rumon

#13 + Middle point = .3
#13 + Right point = .3
Resistor that is in-between Middle + Right point = 5.1k ohm

Im guessing the value doesn't change between the middle vs right point is because it only goes through the bottom of that resistor in its path.

And a quick measure of
#13 + #4 = 5.1k

I'm using a cheap Radioshack DMM, but its close enough that we are getting the same readings

largon

11-30-2007, 01:12 AM

vGPU mod (untested):

edited out

Clint

11-30-2007, 01:33 AM

vGPU mod (untested):

68017

No read from vGPU measuringponits..

largon

11-30-2007, 02:22 AM

Weird. The measuring point should work...
The square pads are on the same plane as vGPU chokes' outputs.

K404

11-30-2007, 03:57 AM

Using a guide on VR-Zone..I was gonna suggest a 100K pot from Pin 13 to ground.

OR a point connected to the FB pin, if it makes soldering easier.

Again....theory, and untested.

largon

11-30-2007, 06:23 AM

INVALID INFO
->

*edited out*

K404

11-30-2007, 06:40 AM

Both Rumon and Miwo got a FB-GND resistance of 5.1K, not 5.1 ohm...or is there a mass mis-communication going on?

Guide on VR-Zone says use a pot of 20x the resistive value of FB pin to GND. Im not pulling numbers out my ass, or making this up as I go along :p:

I admit...taking general 2nd hand info isnt the ideal approach though...

___________________

I agree with the readpoints though

largon

11-30-2007, 07:50 AM

5.1kΩ?
Wowza! You're right!

:O

edit:
Yup.
100kΩ VR would be good.

pinto

11-30-2007, 08:46 AM

It's works well! I use a 100K VR between one green point and the ground, actually testing 1.5v vgpu for 975mhz...

jedimindtriks

11-30-2007, 08:52 AM

It's works well! I use a 100K VR between one green point and the ground, actually testing 1.5v vgpu for 975mhz...

975mhz core??????

and pics please

K404

11-30-2007, 08:53 AM

Excellent :D seeing as largons green markers include the FB pin, il take that as confirmation it works.

Il update the first post.

Please can you try some resistor values for the RAM mod as well, and we can get that locked down too?

K

pinto

11-30-2007, 09:02 AM

Update 995mhz in rivatuner (985 in gpu-z)

http://img98.imageshack.us/img98/8909/3d06152501bc5.jpg (http://imageshack.us)

pinto

11-30-2007, 09:04 AM

K404 i didn't test the ram now, my goal is to find some log where i can clock both cards i own (stupid limit in overdrive to 885mhz)

K404

11-30-2007, 09:04 AM

Congrats pinto, and thanks for sharing. :toast:

Have you added any relevant info about BIOS flashing to the other thread in the 3D section- it looks like you got past the PLL divider fine!?

Miwo

11-30-2007, 09:10 AM

excellent :)
hope my soldering skills are up to the job, those points are pretty damn small
What resistance did you set the 100k VR to obtain 1.5vcore? Are you getting any black screens that would be a hint at OVP ?

Next is a vmem mod, hopefully those gddr4 chips scale well

largon

11-30-2007, 09:51 AM

Some optional solder points marked in green:

68027

quake6

11-30-2007, 12:41 PM

Now it`s time for vmem :D.Is there somebody willing to do that?

nFo

11-30-2007, 01:45 PM

It's time for a: 1GHz GPU clock ;)

K404

11-30-2007, 02:07 PM

The RAM mod is provisonally done as well, but we need someone to try: 100K, 50K, 20K etc pots until theres an increase in VGDDR at max resistance.. sorry- I cant be more precise. If you start at 100K though, the card is unlikely to be damaged

cefurkan

11-30-2007, 02:19 PM

well could we get crysis benchmark test @
1280 pixel
4x aa
high details
in win xp

Miwo

11-30-2007, 03:40 PM

pinto if you could take an actual pic of your mod that would be great, thanks! I just want to double-check before I go about soldering

pinto

11-30-2007, 04:29 PM

That what i gve to a french clocker(no pic of the mods, cards are in the case):

http://img46.imageshack.us/img46/6909/10ok5.th.jpg (http://img46.imageshack.us/my.php?image=10ok5.jpg)

purecain

11-30-2007, 06:12 PM

never volt modded a card before but i'd be willing to do it on these... could do with a simplified guide if at all possible.... ordered duorb coolers ready for the mod...

patrickadizzle

11-30-2007, 06:34 PM

I as well am willing to do it, I did it back on my 7900GT and didn't have a single problem, card still works today too.

ryanmartini

11-30-2007, 10:21 PM

is it possible to get some pics of the final product?

oanvoanc

11-30-2007, 11:13 PM

MonsterMash

12-01-2007, 03:24 AM

Update 995mhz in rivatuner (985 in gpu-z)

http://img98.imageshack.us/img98/8909/3d06152501bc5.jpg (http://imageshack.us)

Need more infos:

It's Rock solid at that clocks? Which temperatures did you get? And with which heatsink? They are the max frequencies? Can't bench at 1ghz?

Thank you.

Bye

K404

12-01-2007, 03:29 AM

thanks for all the effort you make for this mod. :up:

here is a picture of my 3850 - the
strange: the 2 vgpu measuring points ar missing - so does anybody have a clue how to get the right vcore?
(as i dont have any electrician background i hope its not a silly question :cool: )

http://img502.imageshack.us/img502/2047/dscn2700hp1.jpg (http://img502.imageshack.us/img502/2047/dscn2700hp1.jpg)

The voltmod will be the same.

The Choke layout looks to be different to the 3870. Please can you get a picture of the whole of the back of the card?

Worst case scenario will be- take VCore reading from the FETs under the separate heatsink- this reading will be the average voltage so to speak. It will be ballpark right, but wont take into account any droop.

:) K

quake6

12-01-2007, 04:53 AM

Amrita

12-01-2007, 11:57 AM

pinto whats ur idle and load temps(celsius) @ 1,5v/985mhz?
and water temps if u pleas(before the mod was done if possible)

just wanna know if my water loop can handle it before i start modding

thanks for a grait work done guy's been waiting for this

largon

12-01-2007, 01:40 PM

here is a picture of my 3850 - the
strange: the 2 vgpu measuring points ar missing - so does anybody have a clue how to get the right vcore?See those two ceramic caps connecting the copper planes (= lighter areas on the PCB) where the vGPU measuring points should be?
Try poking the pole that is farther from the GPU with a DMM probe... ;)

K404

12-01-2007, 01:48 PM

Where?:confused:

1st post dude! :)

pinto

12-01-2007, 01:50 PM

kyky

12-01-2007, 02:30 PM

I took the advice of Pinto for the vmod.thus I am in watercooling under 1.52V, my frequency is 1012/1323. The temperature of the core is of 44° in full and 41 in idle.

http://img132.imageshack.us/img132/7687/3dmk0635009991368sf7.jpg

Sage

12-01-2007, 02:58 PM

wow great stuff guys :)

i have high hopes for the RAM too :)

Amrita

12-01-2007, 06:03 PM

think i will be fine, i will run way hotter then u but i should still be within good temps
if not i will try reseat my waterblock and maby doo some mod's to the loop
ither way i'm doing this
just need to go get me a new pensil and find me a 100k resistor on monday
again thanks for being guinnie pig's
made my day ^^

ryanmartini

12-01-2007, 07:27 PM

can anyone please take a pic of what the mod looks like? I want to mod mine, but I have no idea what to get, or what it should look like.

Miwo

12-02-2007, 12:45 AM

hit 1GHz on air :) . A big thanks to K404, Largon, and everyone else who contributed! 1.53v measured

http://www.rit.edu/~mkw1084/miwo/3870/3dmark1GHz.jpg

oanvoanc

12-02-2007, 01:06 AM

hi k404

here the picture of the whole card.

http://img101.imageshack.us/img101/7069/img0283af0.jpg (http://imageshack.us)

K404

12-02-2007, 03:06 AM

Hey Oanvoanc :D From the looks of things the mod will be the same. The control ICs and the surrounding SMC layout look the same.
A bit of an assumption, I know, but realistically ATI wont redesign the PWM gear between 2 cards that are so similar.

The VCore readpoint will be different though :)

K

os008

12-02-2007, 03:26 AM

If both cores are practically the same, and only the clock speed is different, shouldn't the 3850 be able to reach 1GHz too? or is it a matter of ... quality of chip?

Clint

12-02-2007, 04:55 AM

The 3850 has some components of lower quality, the vregs...wich I think will not allow it to reach same clocks as the 3870.

Niccolò

12-02-2007, 05:31 AM

If I were you i'd try to shade this resistor, and see what happens
I want to buy this card, just let me know if it works

http://img155.imageshack.us/img155/3989/vmod3850rx9.th.jpg (http://img155.imageshack.us/my.php?image=vmod3850rx9.jpg)

KainXS

12-02-2007, 06:48 AM

I have my 3850 stable @ 776/1125, when I hit 800 theres not enough voltage, the temps I get are 65C full load and 31C idle with the fan @ 70%

http://img221.imageshack.us/img221/7940/3850eq3.jpg

it seems like the 3850 has a lower GPU clock and mem voltage than the 3870.

os008

12-02-2007, 08:22 AM

Kain, i think you should test a game like Crysis while keeping the RivaTuner monitoring up in the background, just to test out the VRAM filled out and working like crazy, cause i think the max stable, unmodded, RAM speed i saw on the internet was 1050MHz, and 776 for the core.

Hope someone tests a V-Mod for the 3850 before i get it next week.

KainXS

12-02-2007, 11:24 AM

I have only tested on battlefield 2 and need for speed pro street so far but if i up the Vcore to 784 card goes bonkers, it needs more voltage.

ryanmartini

12-02-2007, 12:29 PM

Can someone pretty please explain what I need to do to vmod my 3870? I see the pretty 3DMarks, but I dont see what exactly I need to solder on to get the mod up.

Thanks,

Ryan

os008

12-02-2007, 12:37 PM

You need a variable resistance that has 100k and lower, and then solder it onto the 2 points specified in the first post.

Maybe someone can explain better!

ryanmartini

12-02-2007, 01:22 PM

You need a variable resistance that has 100k and lower, and then solder it onto the 2 points specified in the first post.

Maybe someone can explain better!

thanks. where can I find the variable resistor? Would radioshack have it?

Thanks!

Ryan

LordEC911

12-02-2007, 03:46 PM

Ryan- supposedly they do.
There was talk in the 8800GT thread (http://www.xtremesystems.org/forums/showthread.php?t=163929) about it.

As for pics as to what it should look like, something like this (http://www.xtremesystems.org/forums/showpost.php?p=2531822&postcount=121) but on a red PCB with a 100k pot and to the points marked in the first post of THIS thread. That picture is of a 8800GT Vmod.

ghost101

12-02-2007, 04:03 PM

I have my 3850 stable @ 776/1125, when I hit 800 theres not enough voltage, the temps I get are 65C full load and 31C idle with the fan @ 70%

ss

it seems like the 3850 has a lower GPU clock and mem voltage than the 3870.

Hi, which 3850 have you got? Also, does rivatuner overclocking work with CCC installed?

Sage

12-02-2007, 05:30 PM

bring on the DDR3 volts! :)

KainXS

12-02-2007, 09:07 PM

Hi, which 3850 have you got? Also, does rivatuner overclocking work with CCC installed?

I have the powercolor version

Im going to post some pictures of the back of the pcb to help you guys with vmods later

edit

3850

http://www.i-imagehost.com/uploads/e7ad70078b.jpg

yes I know its huge

Glow9

12-02-2007, 10:49 PM

So I see the pic with the green and purple dots what are you soldering to do this exactly? I'm confused

largon

12-03-2007, 12:00 AM

Green = soldering point for outer leg of a VR
Blue = ground = solder middle leg of a VR
Purple = vGPU measuring point (red probe of a DMM to purple, black probe to ground)

ryanmartini

12-03-2007, 08:02 AM

Christmas Project: Vmod 3870 with the DuOrb :D

KainXS

12-03-2007, 10:35 AM

heres the 3850, imagehost keeps deleting it

http://www.yourfilehost.com/media.php?cat=image&file=2127P1010374.JPG

slugzkea

12-03-2007, 02:42 PM

Updated:

These mods need more testing, but initial results suggest they work fine.

Mods are carried out at your own risk. I will not take responsibility for any voltmods gone wrong. No-ones forcing you to mod your cards and invalidate your warranties.

http://img119.imageshack.us/img119/8625/3870corecontrolfinalic3.th.jpg (http://img119.imageshack.us/my.php?image=3870corecontrolfinalic3.jpg)

http://img504.imageshack.us/img504/7303/3870gddrcontrolfinalql8.th.jpg (http://img504.imageshack.us/my.php?image=3870gddrcontrolfinalql8.jpg)

Thanks to (in no particular order)

Rumon, Miwo, largon, Kyky, pinto, pitya

optional core voltmod points (thanks to Largon)

http://www.xtremesystems.org/forums/attachment.php?attachmentid=68027&d=1196445046

Okay so just simplifying here, All you need to do is solder a 500k ohm resistor inbetween those two points?

slugzkea

12-03-2007, 03:36 PM

Okay so just simplifying here, All you need to do is solder a 500k ohm resistor inbetween those two points?

!bump

Electronics store closes in 2 hrs...

LowRun

12-03-2007, 05:06 PM

Okay so just simplifying here, All you need to do is solder a 500k ohm resistor inbetween those two points?

Hmmm... I think you should do some more reading before going for the mod but here you go, VR from one of the green points to the blue point (which is ground), the two violet points are reading points as it says.

slugzkea

12-03-2007, 05:32 PM

LordEC911

12-03-2007, 06:35 PM

How about a pic of the completed mod? The diagram says one 500 k ohm resistor and indicates where to solder the ends (one is ground).

all i want to do is confirm that all you are soldering is one resistor?

If you read the thread, it is suppose to be a 100k VR.
All you need is the card, soldering iron, solder, 100k VR, some wire, preferably double sided adhesive and a DMM.

Unoid

12-03-2007, 10:00 PM

Pinto show us a pic of your mod, We want to see what points u used. What was your finally resistance value to achieve which vcore?

nunchucka

12-03-2007, 10:01 PM

didnt do a volt mod but i used a modded bios and i got 815/2000 out of my 3850..

http://service.futuremark.com/compare?3dm06=4019858

used this bios: http://xxx.iax-tech.com/video/3800biosmod/01.htm

its screaming for more volts i reckon....

tbone8ty

12-04-2007, 01:11 AM

so who is going to fallow through with pics of the vgpu mod?

and why are u guys ordering duo orbs? the zalman vf900 iis better IMO and u can control the fan speed.

just a suggestion.

quake6

12-04-2007, 01:50 AM

vf900 isnt better than duo orbs...

Cha0s

12-04-2007, 04:37 AM

i ordered a S1 Accelero and a 120mm cooler...für my 3850..and this is realy "cool" ^^ its better than the Zalman VF900

Miwo

12-04-2007, 05:33 AM

Just a quick update:
Seems temps are holding me back from reaching full 1GHz stability atm. For instance, at 1.53v 1GHz core, I do not artifact in ATITool until I cross 50C. After a run of 06' my load temps are 55C. I've dropped the vcore down to 1.46v for 24/7 use at 945MHz Core. My load temps after 16hours is 48C, and at this setting it wont start artifacting until I hit above 60C.

My current cooling setup is an Accelero S1 w/ low speed 140mm Yate Loon. Sometime this week, I plan on replacing the Ceramique I used with Coollaboratory Liquid Pro and getting some more airflow across the fins by removing the black plastic caps on the S1. Hopefully that will let me do 1GHz for 24/7 usage on quiet Air :)

K404

12-04-2007, 08:34 AM

A pic (using my uber1337 paint skills)

Please ask yourself...if you are unsure how voltmods work or how they should be attached....should you be trying the work? Remember- the responsibility for the mod lies with yourselves. If you kill your card, its YOUR fault, because the mods have been proven to work.

http://img233.imageshack.us/img233/8936/makingitobviousoj9.th.jpg (http://img233.imageshack.us/my.php?image=makingitobviousoj9.jpg)

largon

12-04-2007, 08:38 AM

If you read the thread, it is suppose to be a 100k VR.
(...)100kΩ is about the minimum, higher valued VR allows minimum voltage as close as possible to stock but they also cause inaccuracy while tuning (larger granularity).

But yeah, 500kΩ might be a bit inconvenient.

os008

12-04-2007, 12:29 PM

thanks. where can I find the variable resistor? Would radioshack have it?

Thanks!

Ryan
I don't know as i'm from Egypt, you have to ask someone who's from your country :).

Unoid

12-04-2007, 03:46 PM

how successful is the vmem for ocing?

STEvil

12-04-2007, 04:09 PM

ryanmartini

12-04-2007, 04:23 PM

To keep from shorting the GPU voltmod you guys might also want to look at putting a fixed resistor in series with the VR... I would say a 10K fixed should do for most but it might be a bit high for getting 1.6v+...

Ok so with the VR soldered to the two points, where would the resistor fix into place?

Also, someone take some pics of the mod, dont be greedy! :D

K404

12-04-2007, 04:25 PM

See my pics on the previous page.

The resistor would be in series with one leg of the pot.

ie: solder point-> resistor-> leg of pot

Unoid

12-05-2007, 10:56 AM

Can someone share with us what Values of resistance equate to vgpu values?

I like toe hard wire w/o a POT. strait resistors ;-) But I'd like to use a smaller POT also. Everyone says 100kohm, but what do you end up at to achieve 1.5vgpu? 15k? 50k? if so I'll buy a 50kohm.
I haven't hard modded since my 9600Pro. Will be fun to volt and watercool again.

1kgpu on water and 1.5-1.6vgpu sounds like fun.

JamesBong420

12-05-2007, 01:28 PM

3850 is here... give me a few days to mess with her then hardmod here we come!!!!!!!!!!! and chiller !!! ! !!:yepp: :yepp: :cool: :rolleyes: :D

winbond

12-05-2007, 03:32 PM

can someone post some real benchmarks of the overclocked 3870?

like crysis 1280x1024 with EVERYTHING maxed out, etc,

thanks

Sage

12-05-2007, 04:49 PM

i can tell you that i run crysis at 1650x1080 with High Everything with a couple of settings Very High.

Though not really any use cause games arnt just dependent on ur gfx card. See my specs below.

JamesBong420

12-05-2007, 08:02 PM

hardmod confirmed to work on the 3850. the stock 3850 volts are 1.22v 100k VR got it to 1.28 im at 1.3 816mhz core and still testing... :D :D :D

slugzkea

12-05-2007, 08:17 PM

I believe my specs below are the most generic for today's setups and my comp should do the crysis bench.

All i need is a photographic diagram of the completed mod and I can get the mod done in less than 30 mins.

I know for sure that 1650x1050 crysis everything high at 877/2600 i get a good 20-30fps or lower.

JamesBong420

12-05-2007, 08:41 PM

x2 3800 @ 3.0
Crucial Ballistix ddr500
msi 3850 823mhz/945mhz

9733 3d06- http://service.futuremark.com/compare?3dm06=4047261

im happy so far... 10k is my goal..:yepp: :yepp:

edit: 3d06 9889
850/999 1.44v http://service.futuremark.com/compare?3dm06=4047847

R*r

12-06-2007, 04:42 AM

ive done the mod but i dont know why every time i set the core clock above 860 it will hang?ive set the vgpu at 1,5 1,4 doesent make any difference?

and if i set the core clock directly at 900 or above the core clock reading show me 34Mhz at riva tuner??very strange???

any one can help?

the-strokes

12-06-2007, 05:01 AM

R*r

12-06-2007, 05:40 AM

thanks man,now im benching @ 1G :up:

JamesBong420

12-06-2007, 07:56 AM

i wish the bios fixed the 3850s 860 mhz lock.... :shakes: :shakes: :shakes:

os008

12-06-2007, 11:39 AM

Guys, what's a good up-to-date utility to edit an ATi BIOS file?

RadEdit, and RaBiT are way too old right now, will NiBiToR work, or is it only for nVidia BIOS'.

Thanks.

Amrita

12-06-2007, 04:29 PM

thank's guys worked like a charm but i had to go 1,5 for a stable 945mhz
next step is to reseat my wb but i'm waiting til i'm adding a new card hafto rebuild my loop then anyway

any fix to get crosfire oc higer yet?

SNiiPE_DoGG

12-06-2007, 07:14 PM

c.freak

12-06-2007, 08:43 PM

Has thee been any confirmed ideal voltage for the VDDR mod? and What VR-size/resistance should this POT have?
I haven't done hardmod since the 9800 and X800 time, so it's been a while :D
For the moment im only doing 900mhz on the core. Boring stockcooler soon goes off.

For the cooling later on i'll be using a triple-radiator + 6x 120 fans for my new MCW60's. Cpu,Nb+Sb will go off with the same cooling. For the moment not really finished with my project. So cooling shouldn't be any problem.

largon

12-07-2007, 12:19 AM

http://www.radioshack.com/product/index.jsp?productId=2062287&cp=2032058.2032230.2032275&parentPage=family&allCount=17&allCount=17&fbn=Type%2FTrimmers&fbc=1&parentPage=family

what do you guys think of this potentiometer for the voltmod on the 3870?It would work but personally, I'd use a multiturn VR.
Single turn pots like that are very inaccurate for vmodding.

SNiiPE_DoGG

12-07-2007, 12:40 PM

It would work but personally, I'd use a multiturn VR.
Single turn pots like that are very inaccurate for vmodding.

ty very much, im off to radio shack!

JamesBong420

12-07-2007, 06:02 PM

finally broke 10k with my x2 3800 - 3850 850mhz/999mhz yahooooooo :D

http://service.futuremark.com/compare?3dm06=4075418

MorGo7h

12-08-2007, 05:53 AM

finally broke 10k with my x2 3800 - 3850 850mhz/999mhz yahooooooo :D

http://service.futuremark.com/compare?3dm06=4075418

Gratz :up:

quake6

12-08-2007, 05:57 AM

finally broke 10k with my x2 3800 - 3850 850mhz/999mhz yahooooooo :D

http://service.futuremark.com/compare?3dm06=4075418

Now go for 11k :D:up:

MorGo7h

12-08-2007, 09:59 AM

Any differences between HD3870 and Vmodded? Since the Vmodded bioses dont work :/

Nvm: I saw some results on page 3 WTF! I want a 2nd watercooling loop!! :p

R*r

12-08-2007, 11:06 AM

finally can touch 15k :D
http://service.futuremark.com/compare?3dm06=4087007

SNiiPE_DoGG

12-08-2007, 11:46 AM

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&Item=150090346325&Category=58164&_trksid=p3907.m29

i got one of these pots for my mod, opinions?

afireinside

12-08-2007, 02:08 PM

100k... All I have right now are 50k :( Anyone know how many ohms are needed for ~1.5vgpu?

Any vmem mod found yet?

K404

12-08-2007, 02:17 PM

afireinside

12-08-2007, 02:31 PM

Ah sorry didn't check the thread. Just got my cards and I've been busy trying to get them to work in games. I'd try if I had 100k VRs but I don't.

And no, I don't know anything about volt mods.

purecain

12-08-2007, 02:37 PM

send your cards back if they dont work in any games, or elaborate...

afireinside

12-08-2007, 02:57 PM

send your cards back if they dont work in any games, or elaborate...

They work... Just not well. Ut3 drops to 30s a lot and CF won't work in hellgate london or crysis.

largon

12-08-2007, 03:18 PM

What is the resistance between vMEM solder points?
Around 4kΩ?

purecain

12-08-2007, 03:20 PM

crossfire does work in crysis on mine, must be a driver issue with your rez and hellgate london works fine for me aswell in crossfire... looks like your having some bad look.
try returning your cards as something is wrong at your end...
are you on vista and have you installed the multigpu hotfix????

afireinside

12-08-2007, 04:00 PM

JamesBong420

12-08-2007, 04:08 PM

hi k404

here the picture of the whole card.

http://img101.imageshack.us/img101/7069/img0283af0.jpg (http://imageshack.us)

here you go at least for the vcore. :cool:

http://buydurango.com/josh_files/vcore.jpg

Klimpen

12-09-2007, 01:53 AM

Hi all, I see a few that want a picture taken AFTER the vGPU mod has been done.
I can provide that because I understand what to do, I have a 3870, I have very good experience with soldering small
components (even SM-components) and of course I have a camera and a webhost..
The only thing I'm missing is a VR of 100kOhm. It's sunday here and EVERY store is closed.
I will ask my friend at work tomorrow for a 100kOhm VR.

Even though I have stock cooling on right now I have a EK waterblock on order so that should be settled in a couple of days.

When I'm done with the mod I will try to take several pictures and help out as much as possible.
Ohh, I have one question though, when I'm done with the mod and everything is ready to go!
How do I know where to start with the VR.
Is it just a matter of trial and error? To start with it set to max resistance (100kOhm) and then
slowly turn it "down" and measure the vGPU readout until I get what I want (about 1.5v)?
I have actually pretty good knowledge in soldering and electronics but have never done a vMOD of this kind before :slapass:

##EDIT##
I have to chose from one of the following ones, any opinions?

http://www.elfa.se/images/lowres/l5560.jpg
type 44 Y for SM with only 10 turns (http://www.elfa.se/elfa-bin/setpage.pl?http://www.elfa.se/elfa-bin/dyndok.pl?lang=en&dok=2012588.htm?_64_324_96)

http://www.elfa.se/images/lowres/l5561.jpg
type 64 with 15 turns (http://www.elfa.se/elfa-bin/setpage.pl?http://www.elfa.se/elfa-bin/dyndok.pl?lang=en&vat=0&dok=2012589.htm)

http://www.elfa.se/images/lowres/l5605.jpg
Type 67W with 20 turns (http://www.elfa.se/elfa-bin/setpage.pl?http://www.elfa.se/elfa-bin/dyndok.pl?lang=en&vat=0&dok=2012590.htm)

http://www.elfa.se/images/lowres/l5596.jpg
Type 89P with 20 turns (http://www.elfa.se/elfa-bin/setpage.pl?http://www.elfa.se/elfa-bin/dyndok.pl?lang=en&vat=0&dok=2012591.htm)

Amrita

12-09-2007, 03:37 AM

i went with the 15 turn's one was acurate enough actualy perfect
a 20 i think u will hate, to mouch hassle turning hehe

as for finding the right resistance u got it right set it too max resistance then solder it on and boot up
messure the volt and start turning a round at a time and messure untill u get a new readout then turn with care untill u hit the sweet spot^^

Mayk-Freak

12-09-2007, 09:49 AM

2 x 3870 Volt-Mod

http://www.abload.de/img/modigst.jpg (http://www.abload.de/image.php?img=modigst.jpg)

JamesBong420

12-09-2007, 11:39 AM

now thats what i call CLEAN!!!! :cool: :p: :D

jimmyz

12-09-2007, 02:02 PM

somebody beat me I see lol. I am still limited to 864 by bios but stilt said soon the 3850 bios will be out. what's worse is i can't get any utility to clock the second card past 770 core.
http://img223.imageshack.us/img223/4488/voltmod007rk4.jpg

Mayk-Freak

12-09-2007, 05:11 PM

C2D@4180MHz -4GB Crucial- 2xHIS HD3870@1012/1341MHz

Vista 64Bit

http://www.abload.de/img/neueergebniosse0fd.jpg (http://www.abload.de/image.php?img=neueergebniosse0fd.jpg)

Unoid

12-10-2007, 12:21 AM

Nice clocks with dual voltmodded 70's.

pepinorang

12-10-2007, 11:19 AM

dude...VMem mod is DONE the only thing missing is the ideal pot value.

Someone should take the initiative and friggin TRY it.

Start with 100K....tune down until it bites then measure the resistance.

Jeeezzzzzz

AFI...I know you KNOW this!

[/exasperation]

I'm on HD3870 (one card 930/1340 and the other 902/1340 ALL stock) I'm just awaiting EK waterblocks and trimmers to do both mods don't worry about it I'm adventurous so I take the initiative ;) will give my feedback here next week I think :up:

Bye
p€p|n0r@ng

kemist

12-10-2007, 12:27 PM

I'm on HD3870 (one card 930/1340 and the other 902/1340 ALL stock) I'm just awaiting EK waterblocks and trimmers to do both mods don't worry about it I'm adventurous so I take the initiative ;) will give my feedback here next week I think :up:

Bye
p€p|n0r@ng

What are you using to clock the cores? Atitool doesnt work, rivatuner works, but only for one core (for me at least), and ati tray tools didnt appear to work.

Ahh ok, was using ati tool .27 B3, will give it a try when i get home, thanks.

JamesBong420

12-10-2007, 12:47 PM

atitool .27 b4 works for me. 3850

http://www.techpowerup.com/wizzard/ATITool_0.27b4.exe

pepinorang

12-10-2007, 04:55 PM

What are you using to clock the cores? Atitool doesnt work, rivatuner works, but only for one core (for me at least), and ati tray tools didnt appear to work.

Ahh ok, was using ati tool .27 B3, will give it a try when i get home, thanks.

Rivatuner works properly for me but there is a "procedure" to follow if you want to clock CF ;) but for me now it's bios-modded :D

kemist

12-11-2007, 11:41 AM

Quick question.

Would it be bad if i were to bridge these two points with solder? It looks like the are connected by the pcb and so it wouldnt matter if the were bridged?

oanvoanc

12-11-2007, 12:32 PM

thanks for your help k404.

here my mod (i didnt use it yet because i already maxed the card out under ln2 without "activating" the mod -> 857mhz)

http://img45.imageshack.us/img45/3167/dsc00631oo7.jpg (http://imageshack.us)

this is a result under liquid nitrogen - without any voltmod.
so you dont need this mod under cold unless the vco clock divider problem has been solved:

http://img107.imageshack.us/img107/4971/061x3850857ja3.jpg (http://imageshack.us)

okok - big surprise - big surprise! :D

today i tested the card just with watercooling - still without activated voltmod.
i kept the temperature below 21 degree celsius (load) and had a stable 857mhz core frequency..... very interesting :rolleyes:

Unoid

12-11-2007, 09:31 PM

why interesting? use the bios that fixes the probelm and 1ghz should be your goal!

oanvoanc

12-12-2007, 04:20 AM

i dont think this would work.
i heard that this bios would just work for the hd 3870.

largon

12-12-2007, 08:11 AM

Quick question.

Would it be bad if i were to bridge these two points with solder? It looks like the are connected by the pcb and so it wouldnt matter if the were bridged?You can do that.
These points are connected via PCB trace already.

chp

12-13-2007, 09:53 AM

atitool .27 b4 works for me. 3850

http://www.techpowerup.com/wizzard/ATITool_0.27b4.exe

It Works??? :confused:

Everytime I try to apply the new values (0.27b3 or 0.27b4) the system crashes. :shrug: I have a Connect3D 3850 512MB.

It work only if I use it in conjunction with RT 206, not alone.

Else, Someone has the resulting values from the 100K VR?

JamesBong420

12-13-2007, 10:30 AM

yup it works for me. make sure you have "if card has 2d 3d clocks,switch to 3d..." is checked and suspend while ATItool is running resume on quit. in the HD 2000 overclocking section. which is in settings. i know dont make any sense but i hope that helps..:rofl:

chp

12-13-2007, 03:45 PM

Unfortunately it doesn't. :mad:

Could it be a conflict with CCC?
Perhaps I missed something?

Sage

12-13-2007, 08:52 PM

bring on the VMEM damnit! i gotta see 1400Mhz at least! :D

afireinside

12-15-2007, 03:56 PM

So does anyone know what the VGPU would start at if I were to use a 50k VR?

jimmyz

12-15-2007, 04:01 PM

So does anyone know what the VGPU would start at if I were to use a 50k VR?

about 1.42
use two and set them both too the max.

oanvoanc

12-15-2007, 04:07 PM

i dont know at which voltage it would start.

but i tested both:

2x50k ohm and 1x100k ohm set to the max.
both result in 1,08v 2d and 1,24v 3d.

(measured on two power color hd 3850 ;)

afireinside

12-15-2007, 07:40 PM

about 1.42
use two and set them both too the max.

Thanks. I'd use 2 but I only have 2 of them on hand and I have 2 3870s ;)

gurusan

12-16-2007, 01:16 AM

I have a Powercolor 3850 512mb and my PCB looks different than those I see pictured in this thread. However, I shaded the circled resistor and managed to get my core to 1012mhz stable :D Temps don't go over 47c load but I am on water.

The thing is, I don't know what voltage I am running...Can anyone tell me where to measure my vGPU?

http://img84.imageshack.us/img84/9079/img2953jk5.jpg

largon

12-16-2007, 05:35 AM

gurusan,
There are several vGPU measuring points in the pic you posted.
All those metallic spots on the bright red area on the far right side of your pic are vGPU measuring points.

os008

12-16-2007, 06:13 AM

So, i got the courage yesterday to do the volt-mod, and i did, and after much testing, i reached a stable 859/999 at 1.4v, max temp of 75c at a 60% fan duty.

Had a lot of trouble getting a cool idle temp with RivaTuner, or even ATI Tool, so i just editted the BIOS of the card to clock itself to 859 on load, and it worked ... no more manual overclock and above all 35c idle temp :).

Just waiting now for Stilt's BIOS, wonder why he's taking so long to post it 0.o

gurusan

12-16-2007, 07:17 AM

gurusan,
There are several vGPU measuring points in the pic you posted.
All those metallic spots on the bright red area on the far right side of your pic are vGPU measuring points.

Which ones in particular? I've tried all them but they give bogus readings like .8 and 1v

So, i got the courage yesterday to do the volt-mod, and i did, and after much testing, i reached a stable 859/999 at 1.4v, max temp of 75c at a 60% fan duty.

Had a lot of trouble getting a cool idle temp with RivaTuner, or even ATI Tool, so i just editted the BIOS of the card to clock itself to 859 on load, and it worked ... no more manual overclock and above all 35c idle temp :).

Just waiting now for Stilt's BIOS, wonder why he's taking so long to post it 0.o

Congrats!!

On a side note...I just did a 3dmark06 run and got 14,815 :D

http://service.futuremark.com/compare?3dm06=4210636

HousERaT

12-16-2007, 08:08 AM

any pencil mods for the 3870?

gurusan

12-16-2007, 08:15 AM

any pencil mods for the 3870?

Is it not the same as the 3850?

os008

12-16-2007, 09:03 AM

On a side note...I just did a 3dmark06 run and got 14,815 :D

http://service.futuremark.com/compare?3dm06=4210636

You can run at 1GHz? how? can you share your BIOS with us please?

EDIT: OH, nevermind, thought you had 256MB version, just saw your sig again.

Thanks.

gurusan

12-16-2007, 10:03 AM

Well I was being stupid before and those metal points certainly are vGPU measure points.

I was at 1.84v :p I have no problem pushing limits but even that is a bit roasty for me on a 55nm process, watercooling or not. So I've lowered clocks to 840mhz.... 1.4v idle 1.5v load ....now temps are 29c idle 37c max load

Would like to figure out a gddr3 vdimm mod for this card, and once I've pushed the limits I will need a new toy :p

http://img135.imageshack.us/img135/4290/temptemptempzh8.jpg

os008

12-17-2007, 10:35 AM

What's the max safest voltage for 3850 please? or in general, what's the max voltage in % that most usually don't pass?

LowRun

12-17-2007, 11:43 AM

Well I was being stupid before and those metal points certainly are vGPU measure points.

I was at 1.84v :p I have no problem pushing limits but even that is a bit roasty for me on a 55nm process, watercooling or not. So I've lowered clocks to 840mhz.... 1.4v idle 1.5v load ....now temps are 29c idle 37c max load

Would like to figure out a gddr3 vdimm mod for this card, and once I've pushed the limits I will need a new toy :p

:eek: :shocked: Now that is some serious volts :yepp:

RealyPssd

12-17-2007, 12:40 PM

Is there any updates/word on when ATI Tool will be updated with s/w voltage control for the HD3xxx's yet?

MsB

12-17-2007, 02:39 PM

Wow thats great gurusan I have two of those cards and I'm waiting for good overclocking tool for cf. I will try the pencil mod when one comes out. what water block are you using?

LowRun

12-17-2007, 03:28 PM

Is there any updates/word on when ATI Tool will be updated with s/w voltage control for the HD3xxx's yet?

No other timeframe than "soon" was given but w1zzard also said that voltage control would be very limited unfortunately :(

RealyPssd

12-17-2007, 03:51 PM

Does anyone know if you can adjust HD3xxx voltages with that new Phenom/790 Overdrive application since it is part of that spider platform?

kemist

12-18-2007, 06:48 AM

Quick question, would this trimmer work for this mod?

Technical/Catalog Information 490-3009-ND
Standard Package 50
Category Potentiometers, Variable Resistors
Family Trimmers
Vendor Murata Electronics North America
Resistance In Ohms 100K

Power (Watts) 0.25W, 1/4W

Number of Turns 12

Package / Case Through Hole

Packaging Bulk

Adjustment Type Top Adjustment

Tolerance ±10%

Series PV37

Lead Free Status Lead free
RoHS Status RoHS compliant
Other Names 490-3009
490-3009-ND
PV37Y104C01B00

Norway

12-18-2007, 10:41 AM

http://img129.imageshack.us/img129/291/3870gddrcontrolfinalql8ux0.jpg

Havent testet it becuase 1350Mhz is more then enough for me ;)

Norway

12-18-2007, 10:51 AM

I have now pencil mod'd the vcore so the circuit is a total off 4.59Kohm, default is it 5.1Kohm

Hope some good results ;)

Sagart

12-18-2007, 11:31 AM

I have now pencil mod'd the vcore so the circuit is a total off 4.59Kohm, default is it 5.1Kohm, what voltage should i expect vcore to be ?

I can calculate it if someone can give me a ohm value at a certain voltage

What's the stock voltage? :)

HousERaT

12-18-2007, 11:37 AM

Norway

12-18-2007, 12:02 PM

It is 1.33v but on my card it is 1.36v stock ......

Norway

12-18-2007, 12:09 PM

I penciled the blue line
http://img409.imageshack.us/img409/2139/hd3870vgpumodsmallke9.jpg

Or any other green spot to GND should work if i'm not completely screwed atm

gurusan

12-18-2007, 12:11 PM

Wow thats great gurusan I have two of those cards and I'm waiting for good overclocking tool for cf. I will try the pencil mod when one comes out. what water block are you using?

MCW60 :)

HousERaT

12-18-2007, 12:23 PM

I penciled the blue line
http://img409.imageshack.us/img409/2139/hd3870vgpumodsmallke9.jpg

Or any other green spot to GND should work if i'm not completely screwed atm
Simple enough....... now lets some some before and after results. :)

Norway

12-18-2007, 12:29 PM

Be patient my young padawan

HousERaT

12-18-2007, 12:29 PM

Be patient my young padawan
I'm waiting like a trick on a street corner. :D

Norway

12-18-2007, 01:31 PM

strange, at 4.6Kohm I got stock volt, on 2.28Kohm i got the same result :(

roger_h99.nor

12-18-2007, 02:10 PM

:eek:
Consider yourself lucky. If, be chance, you've got the right spot to shade, you would have killed your card with that voltage.

Recommend some readup on the basics on v-modding.

gurusan

12-19-2007, 04:22 AM

Is there a vdimm mod for the 3850?

Norway

12-19-2007, 06:28 AM

:eek:
Consider yourself lucky. If, be chance, you've got the right spot to shade, you would have killed your card with that voltage.

Recommend some readup on the basics on v-modding.

Well 4.6Kohm should give me around 1.5v, but it didnt happend so i tried half of it, also tried to shade the resistor but nope :(

Now i have taken som 470Kohm VR from school, but i am only to run stock air for now, water later so i wait for the solder work ;)

TIP: Run your card on 50% fan 24/7, my max temp is 65C load on stock volt on 3870 ;)

KainXS

12-20-2007, 07:21 AM

I just found out something unexpected, one of my 3850's has ram rated at DDR3 1000 and the other has it rated at 900, ATI could have easily overclocked these cards to have 1100 because the 8800GTS XXX uses slower DDR3 800 and can reach 1265, at least on my old one I could.

the voltage on both is 1.8V

Powercolor 3850 XTREME
Powercolor 3850 256

Niccolò

12-21-2007, 05:54 AM

Well 4.6Kohm should give me around 1.5v, but it didnt happend so i tried half of it, also tried to shade the resistor but nope :(

Now i have taken som 470Kohm VR from school, but i am only to run stock air for now, water later so i wait for the solder work ;)

TIP: Run your card on 50% fan 24/7, my max temp is 65C load on stock volt on 3870 ;)

Because that's the wrong spot.

I think i'm figuring it out, just wait a little bit and i'll post the resistor to shade.

Niccolò

12-21-2007, 09:33 AM

KainXS

12-21-2007, 02:17 PM

and that will increase voltage?

Clint

12-21-2007, 02:28 PM

Here it is

http://img249.imageshack.us/img249/6679/dscn2700xp3.jpg (http://imageshack.us)

I had 0.1v increment by reducing it to 1.3 KOhm, so you can count if you want ;)

Ps: obviously there's a K missing between 2.26 and Ohm :up:

Hmm, my default HIS 3870 has a 1.62kOhm value there..:confused:

I did measure voltage and it is 1.34v, so there is something that doesn't add up.

HousERaT

12-21-2007, 02:49 PM

I'm ready to start testing pencil mods as soon as someone demonstrates a working mod for the 3870......... ;)

RealyPssd

12-21-2007, 03:05 PM

Me too, hot damn.

Niccolò

12-21-2007, 03:38 PM

I have a Sapphire 3850 512mb. For me it worked great... Dunno about your card, just try and you'll know it. But 99% i can bet it's the same mod for all cards (that has this pcb of course) ;)

HousERaT

12-21-2007, 04:18 PM

I have a Sapphire 3850 512mb. For me it worked great... Dunno about your card, just try and you'll know it. But 99% i can bet it's the same mod for all cards (that has this pcb of course) ;)
so voltage went from what to what, and how much did it help your overclock?

Niccolò

12-21-2007, 04:51 PM

I only raised it to 1.3v from 1.2v couse i'm on stock cooling.

Overclock went from 750 to 820.

I also tried a 1.35v an this is the result

http://www.pctunerup.com/up/image.php?src=_200712/20071221160627_3dmrd2006864-954-.JPG

Clint

12-22-2007, 12:10 AM

I shaded it down to 1.10kOhm from originally at 1.62kOhm.

Changes were:

1.62kOhm: 2D 1.24v and 3D 1.334v (891Mhz ATI Tool)

1.10kOhm: 2D 1.30v and 3D 1.40v (931Mhz ATI Tool)

(1.00kOhm: 2D 1.32v and 3D 1.415v) (945Mhz ATI Tool)

So it's confirmed working:up:

EDIT: after some testing I can conclude that I have gained 40Mhz from raising 0.07 volt, wich I think is pretty darn good under a stock cooler:up:
I now can run furry cube in ATI tool at 931Mhz, instead of 891Mhz.

Temps went up from 52C to 57C with stock cooler at 80%.

All in all a very sweet mod. :clap:

Clint

12-22-2007, 01:24 AM

Finished a first bench in 3D06 @ 945/1250 without any hickups or artefacts.

Max load temp with stock fan at 100% was 54C.

EDIT: 1 hour of Crysis @ 945/1200 no problemo whatsoever, it actually seems like the stuttering and querkiness that I noticed before is gone...the voltage injection surely did wonders.
Max temp in Crysis was 57C, and I think thats the max I wanna do on stock heatsink.

Next step is to slap my modified 7900GTO cooler on there, 4 6mm heatpipes and some home made high flow ducting will allow 1.5 volt and 1Ghz on air...no question about it.:D

Mayk-Freak

12-22-2007, 05:01 AM

my self modded HD3870 babies:
http://www.abload.de/img/modi3al.jpg (http://www.abload.de/image.php?img=modi3al.jpg)

C2D@4180MHz & 2HD3870@ 1012MHz/1340MHz 3DMark06 19323 Punkte Vista64Bit

http://www.abload.de/thumb/neueergebniossejj7.jpg (http://www.abload.de/image.php?img=neueergebniossejj7.jpg)

magma_man

12-22-2007, 05:41 AM

@ Niccolò & Clint: Can you say something about the difference in power consumption ?

RealyPssd

12-22-2007, 02:32 PM

If I shade that part, is there any way to know what the change in voltage is without a voltmeter?

Are there any applications that can tell me?

Thanks

Norway

12-22-2007, 02:44 PM

Mayk-Freak:

Can you post your BIOS settings ?

ohno

12-22-2007, 04:15 PM

jimmyz

12-22-2007, 04:45 PM

hej everyone.
sucsessfully vmodded my card, have it running @ 1039 MHz and my temps are at 55C, just wondering how far i can go. my volt-meter reads 1.710 during load. thats quite hi, ain't it? what is the max you think...

nobody really knows, maybe you can be the first!!! tell us when it dies and we will set ours .001 v below that :rofl: :ROTF: . seriously though I can do 999 with 1.62 maybe you should lower it some and see if it can still hit the 1039 as before. and what are you using to test?

Clint

12-22-2007, 11:30 PM

If I shade that part, is there any way to know what the change in voltage is without a voltmeter?

Are there any applications that can tell me?

Thanks

I would buy one multimeter ifI were you, a cheap insurance;)

But to answer your question;
I have had a really hard time to shade it down to 1.0 kOhm with a 4B pencil that is very soft, and that has given me 1.415 volts 3D.
I now bench @ 958/1250 no problems, this core scales like a dream :up:

So if you go nuts on the shading I doubt you will get more than 1.45 volts out of it anyway, and that is pretty safe even on the stock coooler.

HousERaT

12-23-2007, 06:43 AM

I would buy one multimeter ifI were you, a cheap insurance;)

But to answer your question;
I have had a really hard time to shade it down to 1.0 kOhm with a 4B pencil that is very soft, and that has given me 1.415 volts 3D.
I now bench @ 958/1250 no problems, this core scales like a dream :up:

So if you go nuts on the shading I doubt you will get more than 1.45 volts out of it anyway, and that is pretty safe even on the stock coooler.
Intersting, sounds like you'll have to shade multiple resistors in order to go higher on the vcore, like how you would pencil mod a 8600GTS.

How are the temps on the 3870 after the pencil mod?

Clint

12-23-2007, 09:30 AM

Intersting, sounds like you'll have to shade multiple resistors in order to go higher on the vcore, like how you would pencil mod a 8600GTS.

How are the temps on the 3870 after the pencil mod?

After adding 0.83 volts I get a temp raise around 6-7C to 58C on the stock cooler running @ 100%.

HousERaT

12-23-2007, 10:41 AM

I can also confirm that the voltmod works. 3870 VCore now at 1.42 after using a #2 pencil. :up:

PPInDaHouse

12-23-2007, 07:01 PM

I can also confirm that the voltmod works. 3870 VCore now at 1.42 after using a #2 pencil. :up:

what image did you used for gpu pencil mod?

VoRtAn_MaDgE

12-23-2007, 07:30 PM

what image did you used for gpu pencil mod?

http://img249.imageshack.us/img249/6679/dscn2700xp3.jpg

This i guess ;)

PPInDaHouse

12-23-2007, 08:43 PM

no, that's for 3850 card, I want for 3870 :)

btw I can run Nature at 1428mhz on rams without any mod, stockcooled :D

but core only 900 :(

Rumon

12-23-2007, 10:41 PM

no, that's for 3850 card, I want for 3870 :)

btw I can run Nature at 1428mhz on rams without any mod, stockcooled :D

but core only 900 :(

Clint, HousERaT and i can confirm that it also works for the 3870.

I managed to get it to 1.49v, Core@958.5 for gaming and 985 3Dmark06

had a hard time shading it though using a 3B pencil

Rick Hunter

12-24-2007, 01:10 AM

Clint

12-24-2007, 01:43 AM

Clint, HousERaT and i can confirm that it also works for the 3870.

I managed to get it to 1.49v, Core@958.5 for gaming and 985 3Dmark06

had a hard time shading it though using a 3B pencil

Excellent!

I'm down at 1.0kOhm...was a real hassle to get it that low, you must have gotten it down to 700-800Ohm or so..:up:

Care to explain the method of shading, did you do circles around the resistor or some other technique?

Menhir

12-24-2007, 01:49 AM

Here it is

http://img249.imageshack.us/img249/6679/dscn2700xp3.jpg (http://imageshack.us)

I had 0.1v increment by reducing it to 1.3 KOhm, so you can count if you want ;)

Ps: obviously there's a K missing between 2.26 and Ohm :up:

I've A GeCube 3850 512MB Turbo 3 Card with an AC S1 and dual 92mm fans

the ressistor is 2.44 kohm on my card default and i measured a vcore of 1.26V

this is a pic of my card

http://img155.imageshack.us/img155/6263/3850markedfc4.jpg

green marked are my measured vcore points
blue is the ressistor i penciled

if i penciled it down to arround 2.00 kohm or 1.8 kohm my measured vcore is lower than default

(around 2kohm it was 1.18volt)

do i measure the vcore on wrong points?

it seams that this is the wrong resistor but my layout is a little bit different what resistor i've to use?

what to do with this card help...

i get 780Mhz gpu clock my card need more vcore :(

Menhir

12-24-2007, 03:35 AM

KainXS

12-24-2007, 03:41 AM

try overclocking the mem and see what happens

PPInDaHouse

12-24-2007, 05:29 AM

so the resistor to shade on HD3870 is the first below:

R1222
R685
R684

that have a black point in the middle?

thanks in advance for the info :)

Menhir

12-24-2007, 06:01 AM

try overclocking the mem and see what happens

even at default memclock (900mhz) i get artifacts with ati tool @864Mhz

when i set the GPU to 850Mhz (there is nothing possible between 850 and 864) i get no artifacts even if the mem is clocked at 1060

i mean 850 is not bad for a 3850 but default 3870 can reach it easiely but not more because of the bios bug

Rumon

12-24-2007, 08:44 AM

Excellent!

I'm down at 1.0kOhm...was a real hassle to get it that low, you must have gotten it down to 700-800Ohm or so..:up:

Care to explain the method of shading, did you do circles around the resistor or some other technique?

I cut the tip of the pencil flat, large enough to cover the resistor.
Then put pressure and dragged it across.

llll
llll --->
llll

I could put a bit of pressure since it was a soft pencil and it simply crushed if it was too hard. I tried it loads of times before i got it to 0.42
If it dose not work on the first 2-3 passes wipe it and try again.

I tried the circular 8 method but that tend to rub it off if you put just too much or too little pressure

(I managed to get 0.38 > 1.45v but was not getting stable expected clocks most likely due to uneven spread)

hope it helps

KainXS

12-24-2007, 03:29 PM

even at default memclock (900mhz) i get artifacts with ati tool @864Mhz

when i set the GPU to 850Mhz (there is nothing possible between 850 and 864) i get no artifacts even if the mem is clocked at 1060

i mean 850 is not bad for a 3850 but default 3870 can reach it easiely but not more because of the bios bug

did you flash the unlocked bios for the 512MB 3850

RealyPssd

12-25-2007, 05:33 AM

http://img149.imageshack.us/img149/5293/pencil1ay2.jpg

i penciled the black marked resistor

it was 2.43 default
i penciled it to 2.22 what gave me 1.40 volt
when i pencil it to 2.19 it give me 1.44 volt

it seems a verry good ressistor for a huge voltage range

i get with my gecube 3850 turbo 3 850Mhz@1.40 volt
but i cant get 864 stable...is it the bios bug?

Which would I shade on my 3870?

The one circled in black or blue..?

Also, it doesn't matter whether or not a multimeter is analogue or digital does it?

Thanks

PPInDaHouse

12-25-2007, 11:43 AM

so the resistor to shade on HD3870 is the first below:

R1222
R685
R684

that have a black point in the middle?

thanks in advance for the info :)

can someone help here :)

Rumon

12-25-2007, 01:04 PM

can someone help here :)

Yes if your board layout is the same its the first resistor below those numbers you mentioned

purecain

12-25-2007, 04:12 PM

BATISTA

12-25-2007, 04:46 PM

hi i have the 3870 club3d when i use other bios the performance is bad in 3dmark, and when i use the orginal than i can go only core 850 mhz ,
can i or can someone modify my bios 4 unlock it ??

i try all the mod bios all the same i can only use the orginal bios 4 good performance

3dmar03 72K@CF 850Mhz Core, and when i use other modbios@1000 Mhz core i get onky 53K with CF

i need unlocked Orginal bios and also need more mhz above 900 Mhz core
i do the Vmod but i cant go above 850 Mhz core
best regard

http://www.abload.de/img/03_72k1x3.jpg (http://www.abload.de/image.php?img=03_72k1x3.jpg)
Withe Original and Unlocked bios i get this score

purecain

12-25-2007, 04:50 PM

Rumon

12-25-2007, 05:45 PM

i just used the pencil mod on the r1222 resistor marked blue on both my 3870's and have no improvement at all.... i used a hb pencil and completely covered the top of the resistor... anyone got any ideas... should i take them out and pencil mod the resistor marked in black???????
any advice appreciated....

Best way to is to use a Multimeter to measure the resistance after you have done the pencil mod.

First time i tried the pencil mod it simply didn't work and the resistance was the same. you will need to get the resistance down to at least 1/1.10KOhms to notice an improvement.

purecain

12-25-2007, 05:55 PM

by re-applying i assume.... am i right? and have i used the pencil mod on the correct transister.. the blue one from the pic... thankyou for you expertise in this matter... i actually dont own a multimeter... i'm ordering one online as we speak.. which is the best to buy... is there a make of multimeter which is known as being the best or will any do... thankyou...
i would appreciate advice on which to buy from this site... money is no consideration... http://www.ni.com/digitalmultimeters/?metc=digitalmultimeters&media=adwords&activity=multimeter

Rumon

12-25-2007, 06:18 PM

Yes your right if it didn't work i reapplied and tried again and the blue one marked on the picture dose seem to be the one that works on the 3870 also.
As for a DMM. I don't know any brand or what is the best as i am just using a bog standard one i bought for back in my electronics course in collage
still works great its something like this.

DMM (http://www.radioshack.com/search/index.jsp?kwCatId=&kw=digital%20multimeter&origkw=digital%20multimeter&sr=1)
(my current ones something along the line of that $20 one)

Also i had a hard time using a HB pencil try something along the line of 2b/3b/4b

BATISTA

12-25-2007, 07:03 PM

cant be done... original bios has a differant hex file... you must use the unlocked version.... i have a thread about it here http://www.xtremesystems.org/forums/showthread.php?t=168407
theres a link to the best performing bios around..... have fun....

hi i try already the bios from the site but no good 4 my club3 i think that the timings alre not good maybe :confused:

purecain

12-26-2007, 09:06 AM

thanks for that m8:up: .... got one on order... i'll redo the pencil mod aswell...

Rick Hunter

12-26-2007, 11:33 AM

Here's my pencil mod results on my HIS 3850 512 MB IceQ3 Turbo.

__ohm Volt MaxMHz Temp
2.26K 1.31V 826 MHz 48
1.38K 1.36V 850 MHz 51
1.45K 1.39V 876 MHz 53
1.13K 1.44V 904 MHz 56

Penciling in 1.13Kohm was not easy.

Scales pretty linearly across the board. Stable in 3DMark06 and AtiTool artifact tester.

I also slapped on a different fan onto the original heatsink, an 80 CFM Delta 80mm @ 70%. Brought down the temps by about 7 degrees on average.

Update:

After a day, the pencil mod wore off a little bit. I redid the pencil mod with the aforementioned technique (over the top of the resistor). Here are the new results:

__ohm Volt MaxMHz Temp
1.13K 1.44V 904 MHz 56
1.19K 1.43V 891 MHz 56
0.99K 1.46V 918 MHz 56
0.99K 1.46V 918 MHz 49 (delta @ 100%)

Ambient temp is about 23-24 degrees.

KainXS

12-26-2007, 11:38 AM

http://img249.imageshack.us/img249/6679/dscn2700xp3.jpg

This i guess ;)

is that really for the 3850, I tried shading that on my 3850 256MB and its not working, anybody got an idea

Wallboy

12-27-2007, 12:51 AM

Update:

After a day, the pencil mod wore off a little bit. I redid the pencil mod with the aforementioned technique (over the top of the resistor). Here are the new results:

__ohm Volt MaxMHz Temp
1.13K 1.44V 904 MHz 56
1.19K 1.43V 891 MHz 56
0.99K 1.46V 918 MHz 56
0.99K 1.46V 918 MHz 49 (delta @ 100%)

Ambient temp is about 23-24 degrees.

Wore off? So when applying this mod, one has to redo it quite often or what?

Rick Hunter

12-27-2007, 07:25 AM

Wore off? So when applying this mod, one has to redo it quite often or what?

Not if done properly heh. I was initially using a thin-tipped cartridge pencil and was going around the resistor many times. Later, I found a regular 2H pencil, wiped the previous application and went over the top of the resistor. I remeasured it today and the resistance was the same.

Bo_Fox

12-27-2007, 10:27 AM

Not if done properly heh. I was initially using a thin-tipped cartridge pencil and was going around the resistor many times. Later, I found a regular 2H pencil, wiped the previous application and went over the top of the resistor. I remeasured it today and the resistance was the same.

Well, then how long would this 2H pencil mod last? LOL... How do you measure the voltages if the measuring points are so far inside of your case? My case is so full of hard drives and cables that completely block any access for me to that area! Any ideas or suggestions for me?

BATISTA

12-27-2007, 01:16 PM

do someone vmem on hd3870 ?? howmuch vmem can i give ??

Rick Hunter

12-27-2007, 11:39 PM

Well, then how long would this 2H pencil mod last? LOL... How do you measure the voltages if the measuring points are so far inside of your case? My case is so full of hard drives and cables that completely block any access for me to that area! Any ideas or suggestions for me?

:) It should last longer than a day if done properly that's for sure. I've got just enough room in my case for the multimeter probes to touch the vGPU measuring points. It's not that easy and one really needs a steady hand while measuring the vGPU. You could always simply measure the resistance each time you try to do the pencil mod and compare that to what my results (or anyone else's) are. Granted, it's less accurate but might be a better alternative than blindly sticking two metal probes onto a running video card. :P I wouldn't go below 1.0 kohm (which usually increases vGPU by about 0.10V to 0.14V) unless you've got modded cooling.

demolitionman1

12-28-2007, 12:40 AM

Hey guys,

here is a pencil MOD for the HD3870/3850 you can check. On my Club3D HD3850 this is 100% functional. The best is, there is no resistor so it is easy to clean. With 4,38-4,40 Ohm I got 1,4 - 1,41 VCore.

http://www.computerbase.de/forum/showthread.php?t=357301

Its in German, but I think pictures says more than words ;)

Demo

Greg_1

12-28-2007, 04:13 AM

I can't get my GeCube 3850 512mb X-Turbo III over 850MHz on gpu :( it has 1.46V at 850MHz everything is just fine little bit over crash, is it bios limitation ?

toddm27

12-28-2007, 05:14 AM

quick question, in the first post for the vcore mod it has 2 pot values, what vcore roughly does the 100k ohm put to the vgpu at max value?

STaRGaZeR

12-28-2007, 06:12 AM

Rol-Co

12-28-2007, 08:37 AM

think this hardmod is working great :D

http://www.hardware.info/images/usersys/benchmarks/002352-8.jpg

toddm27

12-28-2007, 08:45 AM

nice, what volts and cooling? and did you do the mem mod too or just the gpu?

GenTarkin

12-28-2007, 09:11 AM

would appreciate someone explaining those pictures just posted of the new pencil mod. I assume to connect the yellow points with pencil for the 3850...but what is with the blue points? one being the screw...

Rol-Co

12-28-2007, 10:09 AM

nice, what volts and cooling? and did you do the mem mod too or just the gpu?

vgpu 1.52v
cooling: innovatek 7800gtx waterblock's (have 2 cards)

only the vgpu, it look's like vmem has a advantage on that too....i could never reach 1400 until now.

mascaras

12-28-2007, 10:27 AM

Thanks! Can you at least translate the pictures? Seriously, I don't understand a single german word :(

I´ll test it in a few days :)

i think :

yellow >> pencil

Blue/Red >> measuring points

I can't get my GeCube 3850 512mb X-Turbo III over 850MHz on gpu :( it has 1.46V at 850MHz everything is just fine little bit over crash, is it bios limitation ?

do you have the HD3850 bios Fixed or original bios ???

regards