VERY EASY GF6800/le Vmem mod

[S_A_V]

I'm succesfully did Vgpu-mod too!
It was a bit harder for me than Vmem-mod, but still without soldering and pencil!

Before doing this mod I flashed back Leadtek BIOS with default voltages (~1.1V).
Then I set 10k VR to 0.60 kOm and connect it to TP12 and GND (TP4).
Swith power on, see 2.15V at my multimeter and instantly switch power off.
IMHO 2V+ is too big voltage for NV40, so I increase resistance to 2.00 kOm and get voltage exactly that I get with "1.5V BIOS-mod" eg. 1.44V.

Table with resistance/voltage and higher stable memory clock reached in Mother Nature test:
-----------------------------------------------------------------
|Resistance| Vgpu | GpuClk | Cooling target
-----------------------------------------------------------------
| 2.00 kOm | 1.44V | 438MHz | aircooling
| 1.80 kOm | 1.48V |untested|
| 1.50 kOm | 1.55V | 455MHz | very good aircooling (zalman, etc)
| 1.35 kOm | 1.59V | 462MHz | stock/unmodded watercooling
| 1.20 kOm | 1.65V | 466MHz | good/custom watercooling
| 0.90 kOm | 1.82V |untested| chilled water or phase change
| 0.60 kOm | 2.15V | unsafe | better don't try w/o LN2 on GPU
-----------------------------------------------------------------

I set VR for 1.65V and get +60ºc temp on GPU under load with my modified Aucma CoolRiver (in normal mode, without cold water).
Got max stable GPU clock for all 3DMarks: 438@1.44V (before) -> 462@1.65V (after).

In "cold water mode" I already can bench with 450-455MHz at only 1.44V and I test 1.65V with cold water soon (may be on next weekend). I hope with about +25ºc..+30ºc under load GPU can reach freq. like 470-480.

Results of fast testing performance difference:
GpuClk: 438->462 (+24MHz)
MemClk: 1050MHz
3DMark2001: +697
3DMark2003: +490
3DMark2005: +207

Very good prformance increase! Vgpu-mod helps 4-5 times more than Vmem-mod.
I got +20 fps (250->270) for +24MHz@GPU in Nature test / 3D Mark 2001

See pic:


SikaRippa: Yours "fast Vmods for 6800LE/NU" helps very much. Thank you. I not planned running my card at 1.65/3.26 voltage for 24/7. It will be used for a short time when benching, so I hope my card stay alive

ZeroHero: Thanks. I think you have big chance to get 30k too if you do this Vgpu/Vmem mods. Good luck. But if my GPU will runs at 470-480 MHz under cold water then I may get about 30.5k btw beating 6800NU/DDR1 WR on 12pipes LE is my next target