For any 7811FX user who has Black SOD problem...

As you all still remember, there were a lot of threads discussed about this problem, and the ultimate solution seemed to be Rivatuner constant performance ONLY. I've been having this problem for years, but yesterday, I did some rechecking (Mostly because I could not bear the poor performance of this downclocked GPU any more!) and I've found this: The problem seems to be VRAM related, not the GPU itself. I released the constant performance lock, install Nvidia performance tool and set the clock myself to: 600/700 (Core/mem respectively). As you can see, the core clock is equals to the stock one, but the mem clock is a bit lower. Ran some rounds of DMC4 benchmark, play many many Street Fighter IV rounds and got absolute ZERO Black SOD. To ensure my hypothesis, I set the clock to: 500/799 (Lower core/stock mem). Passed DMC4 but failed at the very first battle of SFIV. Well, what I'm thinking is that maybe the Vram was just badly damaged by heat, or something like that. If it's true, may be replacing Vram will solve our problem - if that's possible. BUt I have no clue how to do that, so if any 7811FX user out there still have interest on this and know how & what to do...you know
PS: I'll comeback and check this thread, hope I'll at least get some positive replies till then.

 

Did you try to flash your GPU Bios? it helps in most situations.
For example this thread http://forum.notebookreview.com/gateway-emachines/464520-definite-solution-nvlddmkm-video-crash-p-7805u.html

 

I don't think the P7811fx can have the bios flashed. It is integrated into the regular bios and every attempt from GPUz fails at extracting it.

 

And so the only way to get stability is to lower clocks? What the hell, nvidia?

 

I'm not sure. My laptop have been performing very well last two days (@600/700 core mem respectively). The problem appears to be VRAM only now. If it's really Nvidia's fault, then the core clock must be the one that need to be lowered down.
Can't we just replace the Vram?

 

well the other question is, have you opened and applied any sort of thermal material between the VRAM and the Heatsink?

I can only assume its like every other P-78 series laptop Gateway put out and as discovered during a teardown and confirmed by others, that THERE IS NO THERMAL INTERFACE MATERIAL BETWEEN THE VRAM AND THE HEATSINK... meaning the VRAM is only cooled passively by the ambient air in the case...

Again, this would need more input, maybe someone who has opened their system and applied TIM to the VRAM could comment on the stock memory clock and black screens, however, with no active cooling solution, overheating VRAM modules causing hard locks and eventually total failure is definitely NOT a surprise...


If I am right, and those who opened their systems and applied TIM, dont have this issue or other GPU related issues, then this is definitely not nVidia's fault... (this was an issue with my GeForce Go FX1400 in my Dell D810... cleaned the crappy TIM off the GPU and put some good TIM on both GPU and VRAM modules and have yet to have an issue the last 3 years...)

 

Yes, I did it several times. But I did't know exactly what is used to cool the Vram, so I just reused the stock one. Maybe it isn't as efficient as it was now.
I'm using my Laptop right now, thing have been just fine 'til now. Played alot of intensive games and still zero crash.

 

"did it several times" you mean disassembled the laptop completely? if so and there was no TIM for the VRAM modules, then there is still no TIM for them

This again, is based on the reports that some of the P-78 series had no TIM for the VRAM modules... YMMV with your specific model

 

When I finally did the full teardown I was also changing over to the P79. With the new board I went with ICD for the GPU and all memory chips. With the P79 I find I dont need to OC but I do correct clock the memory as default is 950 and I run at 1000..................

 

Yes. They use something like a 20x20mm sized thermal pad, and only ONE to cool both the core and the VRAM.