ATI 4850/4870 voltmod thread

[Vatos_locos]

i had this card and she died @ 1.5Vgpu

the mods are the same as the others tested post some pics and i will give them to you

[Mr. K6]

Just wanted to post a quick thanks to everyone here. After reading through the thread, I just did my first volt mod on my 4870 and it was a success (did the GPU only). Time to tweak the cooling and really push her .

[Brumi]

i had this card and she died @ 1.5Vgpu

the mods are the same as the others tested post some pics and i will give them to you

Is it a reply for my question?

[Vatos_locos]

yes since my post is under yours i didn't quote it :p
http://www.insomnia.gr/forum/showpos...&postcount=965
see this pic the cpu voltera is on the near the DVI of the cards but the soleering spot is the same as the others cards
dont mined for the wire that leaves from the jumper it is the gnd wire solder it were ever you can as long the pad you choose is ground
if you cant understand the pic post on of your card

[Brumi]

yes since my post is under yours i didn't quote it :p
http://www.insomnia.gr/forum/showpos...&postcount=965
see this pic the cpu voltera is on the near the DVI of the cards but the soleering spot is the same as the others cards
dont mined for the wire that leaves from the jumper it is the gnd wire solder it were ever you can as long the pad you choose is ground
if you cant understand the pic post on of your card

THNX! I try to do pencil mod 1st if it possible.

[SNiiPE_DoGG]

quick question to my fellow voltmodders? (I feel like a a noob but...) What does GPU-z read for 4870 gpu voltage for you?

also anyone running 20ohms on their VRs for 24/7? care to report voltages? thanks

[Vatos_locos]

measure the voltages only with DMM on the Card and not from software 20oHms how much voltages it gives you ?

[wandbeau]

Will this 200k variable resistor do for a 4850 volt mod

http://cgi.ebay.com.au/200k-Variable...QQcmdZViewItem

If not can i use a normal 1k resistor for a volt mod or not?


And the final question whats a good store to buy variable resistors from, preferably in Australia

[SNiiPE_DoGG]

measure the voltages only with DMM on the Card and not from software 20oHms how much voltages it gives you ?

I have done that and I know my card isnt at that voltage haha, but I was wondering if other people got the default voltage in GPU-Z

[Barr3l Rid3r]

hello, I've tested your bios at the CCC the limit is 800 and 1300,
LA if I did try the 720 and 1150 crashes the VGA.
measure with a voltmeter and I have no more than 1.2 volt at full load.
This change does not exceed more than 1.2 volts?
this tension is impossible to exceed 720 mhz and GPU

I hope your comments ..
thank you very much ...
MAURO from Argneitna

New Bios mod for use in ATi 4850 512mb Qimonda w/ or without default cooler.

Improovements:

1) Less Clock and voltage while in Idle mode, bringing better durability an lower idle temps.

2) Higher voltage and default 3D VGPU Clock while in FULL load mode (680/1000Mhz).

3) Higher overclock limit in default ATi CCC driver (800Mhz GPU highest setting) and also better overclock ability cause of the higher default 3D voltage.

4) Adjusted Default cooler fan speed adequately, to keep it cool and quiet.

http://rapidshare.com/files/148699499/4850mod.rom.html



And that is custom made one for hardmodded cards.





Idle GPU @ 400Mhz 1.02V







Full Load GPU @ 830Mhz 1.33V




How to


Windows XP, use last Ati Winflash utility, for Vista must do via DOS floppy disk or Pendrive w/ booting abilities.

Pendrive:

1) Get HPBOOT

http://rapidshare.com/files/107282064/HPUSBFW.zip

2) Get BOOT Files

http://rapidshare.com/files/107282214/USB-Boot.zip

3) Unzip All for both and run HPBOOt, select your pendrive, check quick format and create DOS startup disk, files located at: choose extracted folder containing Boot files.

4) Get and unzip ATiflash 3.60 and then copy the extracted files to your pendrive don`t forget the bios file 4850mod.rom linked above.
http://www.techpowerup.com/downloads...lash_3.60.html


5) Set pendrive as first boot and also first disk in your motherboard bios.

Run:

Atiflash -f -p 0 4850mod.rom

Please post your comments

[Death909]

Since I couldn't find any volt mods, here is my progress: Gainward Golden Sample 4850 uses the NCP5388 PWM controller (only 3 out of 4 phases though), same as the Palid HD 4870 Sonic Dual Edition (end of page 36 for pics). Pin 19 is feedback (inverting input to error amplifier - GPU voltage is set elsewhere, but 8 VID pins is kinda complex) with around 9.5k ohms of resistance to ground. An RT8105 appears to control memory voltage, apparently it's a single phase PWM controller similar to a APW7065 (pin 6 is feedback). Pencil mod is possible though not ideal. I'll wait until I've obtained trimmers and a soldering iron capable of detail work.

Load volts are 1.231v / 2.05v, stable at 765/1100 - though I haven't really tried to push it (just fixed random crashing via reinstalling XP and not underclocking the 2d clocks).

What are the standard / safe overvolt voltages for 0.8ns samsung gddr3? A quick google says 2.05v, though I'd like some confirmation (since it's unstable at 1150, despite 0.8ns = 1200mhz).

[Vatos_locos]

measure the resistant from pin 19 + ground, multiply x20 and this is the VR you need

[Death909]

Will this 200k variable resistor do for a 4850 volt mod

http://cgi.ebay.com.au/200k-Variable...QQcmdZViewItem

If not can i use a normal 1k resistor for a volt mod or not?


And the final question whats a good store to buy variable resistors from, preferably in Australia

Internet wisdom is that you need at least 10 turn or preferably 20 turn trimmer. The one in the ebay link doesn't look like it could even get a full turn in.

A normal 1k resistor will not give you any control / fine tuning, and depending on your card may actually kill it. If the feedback resistance is ~5k (like reference designs), a suitable trimpots would be 5x20 = 100k.

Jaycar sells trimpots (10 turn 100k) (25 turn 100k).

measure the resistant from pin 19 + ground, multiply x20 and this is the VR you need

Uh, yes. I understood that, and mentioned that the resistance from pin 19 to ground is ~9.58k. I'm only lacking tools and components. That and Jaycar doesn't appear to stock 200k trimpots. I still have to measure pin 6 to ground on the RT8105 though. Wouldn't mind having a rough idea of how much the voltage would increase when resistance goes from 9.58k to 9.15k (9.58k and 200k trimpot (set to max) in parallel).

[Brumi]

Here some pics of my card. Anyone can help me to do pencil mod? Is it possible? I find measure points and my gpu get 1,29V full load without any mod. Is it normal?

Measure points:



More pics:

[Vatos_locos]

no pencil mod is not possible as i remember i will edit you pics later today to see where you have to mod the card

[miahallen]

After volt modding, and flashing my 4870 twins with an aggressive BIOS, I've been trying to get a good OC, but not having much success.

This was my first soldiering job ever performed at this level



The problem I'm having, is that while my MM reads 1.310-1.365V depending on the VR position. The reading shown is GPU-Z is always at 1.265V...I didn't look through this entire thread, so this may be a known issue, but I was unable to dig up what I was looking for. Is my vmod working?

At first I figured it was a glitch in the program (CPU-Z), but when my OC didn't change from before the vmod, it really made me start to wonder. Prior to the vmod I'd start having problems around 825MHz...and now after the vmod, I'm still having issues at the same speed. I was expecting to get much closer to 900MHz.

Any ideas?

BTW - I'm still on stock cooling (fan at 100%), and the GPU temp gets up to about 55C under load with 1.365V.

I installed a toggle for the fan, so it'll run with standard temp control, or manually set to 100% by the flip of a switch.

[wandbeau]

Thankyou Death, you saved me a lot of trouble.


Which of the following do you guys think would win in games such as crysis

- 4850 crossfire (512mb) voltmodded of course , and just say the core is at 900mhz and the mem is at 1000mhz

- Single 4870x2 (no volt mod)

- Single 4870 volt modded, i dunno wat these oc to wen volt modded just go on wat others are getting with it volt modded

I want to know this becasue two 4850 volt modded with highend watercooling would cost around same as single 4870x2 with no water.

If this would help the pc specs are

- q6600 at 4.0ghz
- asus maximus formula mobo x48 chipset
- 4gb mem at 800mhz (will be oc to hopefull 1100mhz)

[NBF]

Is there a known pencilmod/hardmod for the ASUS 4850 with Glaciator fan?

Just found out that pcb is a non reference model


Edit: Forgot to mention, pcb is the 3 phase design, same used in some Asus 4850 TOP.

[Dahaka]

Hi, a few days ago i buy a powercolor HD4850, i read all this thread and i have only one question, the bios that you have uploaded works with my powercolor 4850?.

In post #971 is the bios that i want it.

Sorry for my english :P.

[dnottis]

Doesn't matter anymore. As of yesterday the card will no longer boot, just up and died one morning. SDS (sudden death syndrome) hits another HD4870. These cards are garbage, first one was bad off the bat, this one died 3 weeks later.

I'm going to an Nvidia GTX 260 this time.

Just wanted to follow up for all of those that wanted to "chalk it up to your system" as killing the 2 HD 4870s that died.

I've had the PNY GTX 260 overclocked to 756/1566/1242 for the last month, not a single problem. I've had this working longer than either HD4870 lasted and best of all the same hardware. So it was never a problem with my hardware just crap GPUs. Nvidia FTW this round for reliability.

[toyone]

hy
interests me how it is necessary to make it how the vmod the Sapphire hd 4850 dual slot cooler
can you help with this?
thx
(sorry my bad english)

[adrift02]

Just finished another vGPU pencil mod. Using both methods I got the core up to 880 @1.42v. Anyone been using this high of voltage 24/7 for a while?

Its watercooled and uder 40c but I am still somewhat concerned I may be slowly damaging the card over 1.4v. I might back it down to 1.37v...but once you hit your maximum......

[[XC]Atomicpineapple]

Is there a known pencilmod/hardmod for the ASUS 4850 with Glaciator fan?

Just found out that pcb is a non reference model


Edit: Forgot to mention, pcb is the 3 phase design, same used in some Asus 4850 TOP.

I have 1 of these cards. I've just doen the standard hardmod with 100k pot and it works (well card boots into windows OK). Waiting for glue to dry now before I do anything else with it.

Edit. I'm sure I sdet the resistor to 100k beforer soldering the mod, but I've got a core voltage of 1.4v now, which is fine for me but I gather its what people consider to be the upper limit for these cards.

[NBF]

I have 1 of these cards. I've just doen the standard hardmod with 100k pot and it works (well card boots into windows OK). Waiting for glue to dry now before I do anything else with it.

Edit. I'm sure I sdet the resistor to 100k beforer soldering the mod, but I've got a core voltage of 1.4v now, which is fine for me but I gather its what people consider to be the upper limit for these cards.

I would be happy with 1.4V.

My card has a very diferent layout from reference ones, I think Asus has 2 pcb models.

I'll upload some pictures ASAP, hopefully somebody can help me modding that.

[GamerBR]

For people searching for the pencil mod point for the new sapphire card,I've found it.At stock it was 1612 ohms,giving 1.24V .Setting it to 1185 gave me 1.34v.Also the points used for measuring the voltage are different,see the picure(I will use one that other user posted so I don't need to take pictures myself).I'm yet to confirm the memory points,but I'm quite sure where they are,I will post it when I get the necessary cooling for my memories(the stock one doesn't even have a heatsink attached to them).I think this card has great potential for overvolting,with the stock cooler running at 100%,at 1.34v(with no overclock),I get 65°C (GPU temperature with GPUZ) after running Atitool "scan for artifacts" for 5 minutes,and overclocked to 795mhz it gets up to 70°C.



Edit:I was able to get up to 795mhz on the gpu,more than that and some tiny artifacts started appearing on Atitool.When overclocked the voltage goes up a little bit,at stock clock it's 1.335v and overclocked it get about to 1.347v.People with the same card,please let me know your results.