Guide To Volt Modding A 7900GT

[colfin22]

Disclaimer:

I'm not responsible for anybody frying their gpu. Do this at your own risk. I also wouldn't recommend this on the stock cooler.

 

I know this is covered in another thread, but this is an easier guide & shows my before & after results.

 

The 7900GT operates at a stock voltage of 1.2V, connecting any or all of the coloured dots in the pic to ground increases the voltage by painting a conductive line with a conductive pen. There are several mods, 1.25V, 1.3V, 1.35V, 1.4V, 1.45V, 1.5V & 1.55V

I chose to do the 1.5V mod as this is what the chip is actually rated for and nVidia have it underclocked to 1.2V. The best thing about this mod is that it can easily be reversed & is not permanent.

 

 

More info on all the mods:

http://www.planetamd64.com/lofiversion/index.php/t21181.html

http://sg.vr-zone.com/?i=3330&s=2

http://www.vr-zone.com/?i=3437&s=1

 

Before:

 

I've had my 7900gt oc'ed to the maximum i could on stock voltages. If i went any higher i got crashes in 3Dmark. Here are my before settings & temperatures:

 

 

idle temp: 38'

Load temp: 52'

 

3DMark05: 10672: http://service.futuremark.com/compare?3dm05=2236197

3DMark06: 6067: http://service.futuremark.com/compare?3dm06=522108

 

Memory Mod:

 

To do the volt mod you need a multimeter & a pencil. Gently shade the resistor in the pic below (marked VMem) until you reduce the resistance from 608 Ohms to 553 Ohms. This is tricky as you need a steady hand to touch the ends of the resistor with the multimeter probes.

 

 

Volt Mod:

 

Using a conductive pen, connect the points in the pic below. I had to remove the metal plate on the top of the gpu to get room for the paint. I got my sis to buy the conductive pen for me in NY as it was E40 in Maplin in Ireland.

http://www.radioshack.com/product/index.js...rentPage=search

 

 

This is very tricky & will take several attempts to get right. Make sure you have acetone & a cloth ready. I practiced drawing lines with the pen on a piece of cardboard first, & still had to rub out & start again about 6 or 7 times.

 

 

Results:

 

 

Idle temp: 41'

Load temp: 72'

 

3DMark06: 7054: http://service.futuremark.com/compare?3dm06=527383

3Dmark05: 12386: http://service.futuremark.com/compare?3dm05=2241811

 

Quite impressive, don't you think . Of course i'm not gonna leave my clocks up that high & have them dropped to 700/885 for everyday use. I also added 2 heatsinks to the back of the card as in the pic below. Sorry bout the bad quality, will update with a better pic later.

 

 

I also had to turn off driver testing in Rivatuner to allow me to clock higher. You do this in Power User in the overclocking global settings section.

 

Good Luck

[Redbeaver]

*I also had to turn off driver testing in Rivatuner to allow me to clock higher. You do this in Power User in the overclocking global settings section.*

 

you should highlight this nice little guide

[colfin22]

*I also had to turn off driver testing in Rivatuner to allow me to clock higher. You do this in Power User in the overclocking global settings section.*

 

you should highlight this nice little guide

 

Done

[Guest Retratserif]

Is there any suggestions for memory coolers and or the heatsinks for the back of the card? See I have water on mine and I have yet to go further than the clocks in my sig.

[Glitch05]

Hi.

Good tutorial. Is there anywhere that has an easy to follow guide to using Rivatuner? I have a BFG 7900GT OC, -in sig- and I whacked a Zalman vf900 on it and did the volt mods and can only get 550/1500 out of it.. Any Ideas? My temps are all good, its got plenty of juice. In CS:S I get some nasty texture errors that go away if I reduce the clocks but I should be able to have this thing stable at way higher clocks right?