ATI 4850/4870 voltmod thread

[noinimod]

ok... can the CCC's autotune be trusted? Cos i just ran it for fun and it detected the oc-ed clock for my 4850 as 775.
Is that a good thing or what? I'm still on stock so i might be able to push it even further with a aftermarket hsf, without resorting to voltmodding yet.
What do you guys think?

[madaba]

Just be going a few quick passes with the pencil i've been able to gain 90MHz so far on the gpu on my 4850's. They were running at 1.20 and by just adding .05v I've had them running stable at 750MHz

[joshua7]

joshua7, why not?

Don't wanna screw up.

[gurusan]

Great!

Well, tbh, I never saw the point of pencil modding. I want to set the optimal vGPU by running ATitool or something, clocking and adjusting the vr "live", to find the best balance between clocks, voltage and heat. This is ofc not possible when pencil modding.

it is when you pencil to a set voltage and then fine tune voltages using the BIOS voltage tables.

This was great with the 4850 but the voltage tables seem very limited on the 4870. I'm looking for a bios with an idle voltage of under 1V but the lowest I found is a sapphire bios with 1.1V

[Jim M0rrison]

it is when you pencil to a set voltage and then fine tune voltages using the BIOS voltage tables.

This was great with the 4850 but the voltage tables seem very limited on the 4870. I'm looking for a bios with an idle voltage of under 1V but the lowest I found is a sapphire bios with 1.1V

Yes, that, or sitting there with a DMM, watching artifacts dissapear at the right turn of a screwdriver!

But yeah, ofc I understand some prefer pencilmodding

Got a crapload of work atm, but aim to mod my Powercolor rev2 4870 (non-reference pcb) by next weekend. Will return with results and hopefully, some pictures!

[icewaere]

Hey,

i have bought an MSI R4830-T2D512-OC Edition (V153-001R) and this card works very well at 750/1120 Crysis 30loop stable on Stock
this is a 4+1 phase Pcb.

but now i want more anyone know how i can do an pencil mod on this layout?

here Pics but nor the best ;( if you need better pics i will try again for better ons.

PIC01
PIC02
PIC03
PIC04
PIC05
PIC06
PIC07
PIC08
PIC09

Hope anyone can help me for vMod and MemMod

greetz & thx ICe

[ceemic]

icewaere, http://ceemic.pri.ee/hardware/rt8802a.JPG
I marked FB pin trace. You see that there are 3 SMD capacitors and 2 SMD resistors that are connected to FB. Use DMM to search GND on the other ends of them. If You find one, You can use it for pencil mode. First measure default resistance between FB and GND for reference.

Seems nice card to play with. This IC can actually control up to 5-phase PWM

Good luck

[8800's@over]

Celebrities,

I will open my card (4870) this week, I can pass Artic Silver 5 on top of the Ram chips and VRM?


If I can pass q withdraw termicas blankets?

[icewaere]

hey ceemic thx for fast reply

ok thats my first vmod plz give me a little help with that.

ok with DMM i must search the GND from the bottom of the 3 SMD capacitors and 2 SMD resistors right?

wich settings i must do on DMM for that? 20k Ohm?

how i find the right one?

plz sorr my first time plz little hlp

greetz ice

[ceemic]

icewaere, put Your DMM to lowest resistance reading (ie 200ohm). Put one stick to some GND You know (ie GND in PCIe connector) and with other end start measuring the SMD components. It must read 0,00ohm, so You'll know its GND.
When You have find the right one, put Your DMM to bigger resistance(ie 20kohm) and measure the resistance between two sides of that component. Then use a pencil to lower resistance. Don't forget to check the resistance drop after every stripe You have done.
Lower the resistance for example 10% at first and then turn on Your PC to check, how much Vgpu rised!

[icewaere]

ahh ok great

i will try this evening. thx for explain.

i post the result if i found

greetz ice

[Oztopher]

Hey guys, this is my second pencil voltmod on a graphics card (1st one was on 2x3870's - worked out ok!) I have HIS 4850, w/ a blue PCB, doesn't look like it's a complete non-reference, but there are some things different, like - the 2 places to shade in with a pencil have been swapped ! and theres a few caps missing from the VRM area... which is.. crap (btw, how would this affect OC'ing ? or the card in general ?)

Now, with the stock cooler, i was able to get 670/(still working on mem atm, its a bugger to find stable...) Yeah.. not the best. But anyway, i whacked on a T-rad2 and 2x92mm fans.. and my my is this SO good ! when i 1st booted up, was getting idle temps of 20-22*c ! load was around 32-33 with furmark after 10 odd minutes, i'd say room temp was 15-20 odd degrees - pretty chilly (i have antec900 with plenty of airflow though.)
This is how i had the sinks setup - http://www.virtual-hideout.net/revie...cs/TRAD212.jpg
I'd highly recommend it. Clocks weren't that much better with this on, i think they were 675-680 on core, can't remember

Now to the voltmodding ! I tested the ohms with my left-behind british gas DMM (which the brand happened to be called fluke !) and twas 2654ohms, which equaled 1.18v on load. I lowered it to around 2450ish, which gave me 1.29 on load. I got a 750 coreclock out of this, (using Rivatuner to OC!) 755 failed furmark, funny how a managed to get 750 exactly with one tweak eh? Temps were closing in on 35*c.

Now, i then went for more, tweaked ohms, 2400. 1.33v on Load. I managed a 775 coreclock, anymore - fail. Temps were getting closer to 40.

Now, this is when i went aiming for my 24/7 voltage, 1.38v. I lowered resistance to 2300, managed to get near enough- 1.38v on load !. I tried 800 on coreclock, seemed furmark stable.. knocked it to 825.. furmark stable. Temps were around 40*c. Then.. i just looked into my case, and happened to see an almost browny yellowish-ness on some of the solderings ! i crap myself pretty much, stopped furmark, took out card and erased pencil mod.
http://www.techpowerup.com/articles/...s/overview.jpg
In that pic, the solderings points to the right of the green sticker and around where it has stamped 'test passed' (inc one of the vgpu measure points) had this yellowish goo around them, not ALOT, but noticeable up close. I can't remember if it was like this when i 1st got the card, but ofc u would understand im being cautious about my new card. Have any ideas? a mate told me it might be flux, but is this good or bad ?! should i continue my voltmod ? Temps were NOT an issue.

Cheers if anyone can help,

Oz

[Jimbo Mahoney]

Jimbo Mahoney, other markings on IC are irrelevant. Yes it is the same pin 13

Thanks again.

Successful vMod here - I found a nice place to solder to - resistance to ground is 2.83k and 100k gives 1.28v.

Default vCore for this Powercolor 4830 is indeed 1.25v - now running 1.3v but yet to test overclock - was 775 Mhz on 1.25v with water.

[icewaere]

ceemic:

ok results. plz take a look at pic.

PIC

i have found GND 0,000 on this 2 SMD resistors and on both i have an resistance of 1,04Ohms.

You think ths the right ones? I have do a little pencil on R2 but no Ohms change. dont know why ;( i have used a standart pencil.

have i used the wrong pencil or why no change on ohms?

greetz ice

[ceemic]

icewaere, are You sure, it is 1,04ohm, not 1,04kohm? You can double-check the resistance, when You put one DMM stick to pin 4 and other to GND on PCIe. But I think You have done it right.
Use "regular" 2B pencil.

[icewaere]

ceemic:

ohh sorry yea right 1,04kohm on DMM 20k setting.

you think all 2 smds i have marked change vcore or only one of them?

greetz

[ceemic]

It does not mather, asfar it connects FB to GND. Use only one of them.

[icewaere]

ok i will try again now give me 5mins

[icewaere]

ceemic

hehe ok it works after 5pencils i have 1,019kohms and now 15mhz more stable after 750mhz now 765mhz

PIC
PIC2

max temp core 44c and mem 50c i love that stock cooler.

ok now what you think how many is more possible? 1,000kohms?

you know where i can find Vcore pins for read out?

you know if possible for Mem too? its great Samsung 831 K4J52324QH-HJ1A on it.

greetz and thx for hlp
Ice

[Jim M0rrison]

...
you know where i can find Vcore pins for read out?
...

Hey there, good job on the pencilling!

I have a suggestion for your Vcore readout:



I am far from an expert, so you should get this confirmed by Ceemic or someone else, more knowledgable. However, it won't hurt you to try those points with your DMM. If you get 1.1-1.3v or so, you are probably in the right spot. The components are, as I understand it, the "phase regulators" (maybe not the correct term?), and you probably have one more out of picture. They would all read the same voltage at the base plate thing I circled (if I am correct).

Good luck and please return with a report

[icewaere]

hey,

thx Jim M0rrison but on this pins i have 12v.

hope ceemic can help.

greetz

[ceemic]

Yes, the big legs on mosfets aren't right. Why didn't You check the other two?
http://ceemic.pri.ee/hardware/4830_vgpu_mon.jpg
Use coil or cap legs

[Jim M0rrison]

Sry icewaere, didnt mean to mislead you

Yes, the big legs on mosfets aren't right. Why didn't You check the other two?
http://ceemic.pri.ee/hardware/4830_vgpu_mon.jpg
Use coil or cap legs

Yeah, but now you are making me a but worried here! The reason I suggested icewaere to check those point were that those read 1.3v on my 4870... :S Do I have the wrong points then?

[icewaere]

Ok ceemic great i have found and MemV too look at pic

PIC

@ 1,00kohms i have 1,16v
now litte pencil = 0,95kohms = 1,18v

great it works now 775mhz stable 30 crysis loops

now next how much can i giv the Gpu 1,26v ??? or what you thinking.

and any idea where i can find pencil vmem resistor?

greetz ice

[icewaere]

Ok my firend its done


--> MSI HD 4830 OC-Edition (V153-001R ) @ 800MHz*1175MHz vMod 1,26v <--

look Valid: LINK

and Crysis 30 Loops rock stable:



Temps at GPU 55c and Mem bei 60c. becaus 10c + as Stock. And all with Stock Aricooler and without Ramcoolers

Here vGPU Mod from CeeMic and ME:



Think is a amazing Overclocking for this cheap Card

Also it must be worked on MSI 4850 Card with 4+1 Phases too i think.

Hope we can do an vMem Mod too

greetz Ice and special special THX fly out for ceemic