Volt mod - 7800GTX

kenc51 · Post by **kenc51** » Wed Dec 21, 2005 9:32 am

Hi all,

I'm getting my new GFX waterblock after work today

Now, the 7800GTX GPU runs @ 1.5v stock?

Does anyone know what's the safe voltage for this chip?
I know to keep an eye on temps, but I don't want to kill the card (@ least not yet ;) )
I was thinking 1.6v should be fine, but If I can go higher all the better

Bio-Hazard · Post by **Bio-Hazard** » Wed Dec 21, 2005 9:57 am

You might try ovr here. They do alot of that sort of thing.

http://forums.extremeoverclocking.com/s ... =volt+mods

Post by **Apoptosis** » Wed Dec 21, 2005 10:16 am

Most run at 1.2V in 2D mode and 1.4V in 3D mode.

Solder a 15turn"multi turn" 250 ohm vr or 2 1k vr's in par. to these two points. "do not exceed a 500ohm vr as jumps are too great". the resistor is the circuit the solder pad is ground so feel free to use another ground instead of this tiny tiny solder pad..

7800vcore
http://img93.imageshack.us/img93/499/7800vgpu9nq.jpg

7800vcore mod area and read point
http://img36.imageshack.us/img36/4726/7800corea0kt.jpg

I personally wouldn't go over 1.6v on the GPU and on the GDDR3 memory I would stop at 2.25v. If you are water cooling you might be able to go higher, but watch the temps!

edit: http://www.malvescorner.net/7800.html

kenc51 · Post by **kenc51** » Wed Dec 21, 2005 11:12 am

I should have mentioned, I'll only be doing a bios mod for the GPU vcore!

I killed a Gforce 4 4400 trying a vdimm mod b4........my soldering iron is too big and I'm too clumsy LOL

I'll post some 3dmark results later..........I'm off work in 20mins, should have the cooler in 30mins......OC'ing in about 1hr... ;)

kenc51 · Post by **kenc51** » Thu Dec 22, 2005 2:31 pm

I used NiBiTor to mod the bios.....the highest vcore I can give is 1.5v

It doesn't help either, I'm stuck @ 490MHz

I was hoping to hit 9K in 3dmark '05....