8800GT voltage mods

[jason4207]

Try the BIOS mod anyway. Perhaps you are getting a bad read w/ your DMM. I get readings of up to a 0.05v difference depending on where I put my ground probe.

[Demo]

Try the BIOS mod anyway. Perhaps you are getting a bad read w/ your DMM. I get readings of up to a 0.05v difference depending on where I put my ground probe.

But seeing as how it overclocks now at a very low level, its not worth the hassle.

[Renegade5399]

OK, so I finally bit the bullet and performed the vGPU mod. My RAM already does 1000MHz so the vRAM mods were not needed. I still need to do the OCP mod. With it as it is right now I can do 864/2000/2000 and all benches will complete. Without the OCP mod, you really have to "sweet spot" the voltage setting so not to trip the OCP while keeping stability. AM3 and 3dMark01 (yes 01) are helpful for this. Once 3dm01 hits the multi texturing test, voltage will spike due to the load. So right now I am running 1.295v idle and it goes up to 1.337v - 1.355v under load. 1.4v on the meter will trip the OCP and I get the black screen and 0 volts on the meter. I have to say though that while I am seeing better bench scores, the scores didn't scale like I was expecting. Still, this thing performs AWESOME! Thanks for all the tips. Now it's time to sell this and get a GTS, LOL!

[nvrmind]

If default vmem voltage is 2.0v, and you use a 20K resistor for the vmem mod what is the lowest and maximum voltage you will be able to achieve?

[r4st4m4n]

Seeing all the nice number people were getting, I finally decided to jump into the train. I bought a solder iron, DMM, all the hardware needed for the Vmod and a HR 03-GT to replace the stock cooler.

Everything wasn't smooth but at the end I finally managed to get it working.

Here is my max AT stable OC before the volt mod: 712/1728 @ 1.1V load temp 78*C


Here is my current max AT stable OC after the volt mod and the installation of the HR 03-GT 783/1890 @ 1.2V load temp 51*C


Picture of the moded card: (not very pretty but it does the job :p)


Turns out pretty good for a 1st volt mod and considering that I had never soldered anything before.

A big thanks to the extremesystems forum members for all the useful information that gave me the guts to do it and particularly to Largon for the volt mod and to Thrilla to post this awesome soldering guide: http://www.xtremesystems.org/forums/...d.php?t=115387

[Renegade5399]

LOL wow, I mounted my VR on the same corner! And the Molex connector is a MUST. Good job on your first volt mod!

[r4st4m4n]

LOL wow, I mounted my VR on the same corner! And the Molex connector is a MUST. Good job on your first volt mod!

Thanks

I actually took both ideas (molex and VR placement) from pictures posted on this forum (maybe yours ).
This is the advantage to have many skilled people here: it avoids beginners to make too much mistake and allows to know great tips

I've continued my testing and succeeds to run 10 loops of Crysis GPU benchmark and 2 loops of 3dmark06 at 799/1998/975 @ 1.2V idle.
This card definitely needed better cooling and more volts to shine
After finding the max OC at 1.2V idle, I'll try up to 1.3V