7900 GS / GT Volt Mod

[Cupcake]

This mod applies to nvidia reference PCBs (XFX usually does not apply)

XFX New PCB VMod Here

Materials...
Conductive ink
lead pencil (6B Work the best , Any will do)
Some good music
Chips and dip


Heres the backside of the card with the mod spots marked off



Take your conductive ink and draw a trace connecting these three components



Close up of Memory Resistor Shading mod



AND, For those of you with stock cooling or halfway decent air cooling

Here are smaller vmods , same traces though

on stock I wouldnt recommend going above 1.3v unless you have extremely low ambient temps



Heres The Cooling im using Gets me 32c idle and 34c load with 25c Amb


Results so far




Now Give yourself a Pat on the Back and have a nice Sandwich


Thanks for reading , Please leave feedback Also if you tried it please share your results

[kevinbo03]

Very cool!

I've got a GS right now with stock cooling, And I may be getting a new Air HS \ WC setup... What voltages would you suggest for Air? 1.4?

Also, what are the specific diagrams for Mem volt mods?

[ziddey]

what vmem are you using to get 1000?

[nullface]

Uff 1Ghz mem, how are you cooling the samlle chip?

Getting a FC79 too, so ill be doing the big mod too.

[Cupcake]

Its under the EK Waterblock , Im using about 2.3 (if im not mistaken) on the memory

I have to cool about 4 different chips on the top of the card now , one of them never used to get hot ????

[NightRaven]

haha its tt grp of ics at the vmem mod there right? cool them down to get less artifacts in 3dmark

[nullface]

Its under the EK Waterblock , Im using about 2.3 (if im not mistaken) on the memory

I have to cool about 4 different chips on the top of the card now , one of them never used to get hot ????

Im a bit unsure now, are all the chips that have to be cooled under the FC79?

Just got mine today YAY!

[nullface]

How much cooling does the mem chip need?

(I assume its the one with "6549CBZ P548C4D" on it)



I have some Zalman VGA sinks, would one of them be enough?

http://www.levicom.de/xilence/en/xpram.htm

[Cupcake]

It would most likely be enough , I have some pretty cheap copper sinks on mine and they get pretty damn hot but not hot enough that im worried

I run 2.3v BTW

I would say a zalman sink would be enough as long as you have some airflow around it

[nullface]

Ok, nice.

But just to get it allll straight.
All the chips that have to be cooled, get cooled by the FC79, exept the mem chip.

And am i looking at the right mem chip? the one with "6549CBZ P548C4D" on it?

[Cupcake]

that depends.... whats the FC79 ? lol

but actually I use 3 ramsinks on mine

I will get pics of where they are in a minute

[Cupcake]

Here you go mate, I put little comments about what im using

Id ask someone with more experience which chips actually need to be cooled

[nullface]

I thougt you use a EK FC79 waterblok?

Many thanks, a very usefull picture Ill put sinks on all of them

Hm, maby the Xilence sinks are not even enough

[Cupcake]

I just didnt know it was called the FC79

[Demo]

Even the Rev2 boards still have that heat problem by those chips but not as hot as rev 1

[Cupcake]

im guessing mines a rev 2 cause I only got it about a month ago

[SaII]

Can you clock your core higher?

mine clocks 630 on default voltages

EDIT: ops stupid me, 500 is the default

so how high can you clock your core with the volt mod?

[Cupcake]

oh , 720 stable

I hit 850 once but it froze up in seconds

wish I had a screenie of that

[nullface]

Here you go mate, I put little comments about what im using

Id ask someone with more experience which chips actually need to be cooled

I am looking all over Denmark for a decent pencil, and i think i found something.

But befor i start, i just wont to know, it the chips that heat op at the buttom of the image, do they only heat up when you do the memVmod?

[Cupcake]

I think the ones at the bottom of the picture get hot from the mem mod and the top ones get hot from the core mod

Im not sure so feel them after doing your mod

[Vatos_locos]

hey i cant find here a condactive pen if i do the mod and just wired the will it work ? i don't have any problem to solder a wire on the

[ziddey]

sure

[Vatos_locos]

thanks man i have already soldered it tomorow i will try the 1,4 mod i just hit 620/900 memmory on 2.1 core on 1.3 not bad it gave me 23.174 on 3Dmark 03
and the temps i hink they are good 45 idle 58 on load with one zalman 900cu led (i think this is the name)

thanks again

[Vatos_locos]

ok i need some help now i set 1.4 the Vcore and 2.4 the Vdimm how much up can i go now safe i have 660Mhz on the core and 1000Mhz on he ram i have hynix chips can i raise more voltage on the rams chips is it save to go above 2.4 Volts ?

[ziddey]

2.4v is WAY TOO MUCH. i wouldn't go higher than 2.2v or so.

the 7900 isn't memory bandwidth starved anyway, so raising memory that high would net you hardly any improvement.

Also, if you raise vram to 2.2v or beyond, you should put a heatsink by the ic next to the mod, because it will get very hot and cause instability.

as for core, what temps are you getting under load? what are you using to cool it? if you have good cooling, you can give 1.45v or 1.5v a go.