pls help, problem overclocking a GPU

rcarlos243 · October 5, 2014

my brief specs:

Intel Xeon E3-1230 V3

Gigabyte Z87X-OC

MSI GTX 780 Twin Frozr OC 3GB w/ NZXT G10 Bracket + Corsair H110 280mm AIO Liquid Cooler

Seasonic X660 Platinum

more info of the GPU:

It is revision B1

It is using Hynix Memory

I am using the latest driver (344.11)

Default Clock: 902 Mhz Core, 1502 Mhz Memory, 954 Mhz Boost

Stable Overclock w/ stock voltage(highest I saw was 1.1620): 1030 Mhz Core, 1845 Mhz Memory, 1082 Mhz Boost (1137 Mhz Max Boost while gaming)

the absolute highest gpu temp I saw while stress testing was 54c.

I tried to verify my gpu core overclock stability through EVGA OC Scanner X(artifact scanner), Furmark, Unigine Valley and I never got any artifact, flickering, etc... but as soon as I play a real game (Grid Autosport) it crashes(It never crash while on stock).

Right now the only one that seem to actually test the stability of my GPU core overclock is OCCT with error check. I was able to set the base core clock to 1030Mhz and it seems to be stable as It never crashes on game or show any weird stuff.

In comparison to OCCT other programs such as EVGA OC Scanner, Furmark, etc make it seem like my overclock is stable (1115Mhz on core) as it never shows any error, artifact, flickering, etc... on those stress test but the overclock fails on actual games.

The problem with OCCT is that it doesn't detect errors for memory stability. As an example If I overclock the memory (like 1900Mhz), It would just pass the OCCT error check (even with the option for memery used to the max) but when I play game I get a microsecond black screen so I have no reliable and efficient way of actually testing stability of memory overclock (I got my 1845 Mhz overclock by playing an actual game and reduce the memory frequency by -5 till I don't till I don't get any microsecond black screen). OCCT also doesn't load the Max Boost clock while stress testing (the max for GPU core was 1058 Mhz and 1.0870v).

I also encounter a weird problem that if I overvolt the GPU (even with the absolutely lowest added value), the performance got worse (on OCCT the FPS drops by about 15-20FPS). Adding more and more volt makes the performance drop steadily with every volt increase. The only thing I think what is causing the problem is the Power Limit/Target, My GPU only allows a maximum of 103% and I suspect I am reaching the power limit by adding voltage (changing the priority to temp does nothing). I am considering flashing another BIOS or more specifically the MSI GTX 780 Lightning BIOS as it allows up to 109% power limit but I am not sure if it is safely compatible (I heard that on some BIOS like on the R9 290 with Elpida Memory, there was a bug where if you overclock the memory, the memory timings gets loose which affects the mining hashrates performance more info: HERE) (to clarify, I am worried that different BIOS might have different memory timing setting). I also considered the Kepler Bios tool but I have no Idea how I could edit it to increase the power limit from 103% to 109% or something.

To recap I need:

-A reliable(one that actually WORK) and efficient(doesn't take 100 steps and hrs) way to test stability for the gpu core AND memory(especially) overclock

-increase the Power Limit/Target from 103% to a higher figure (like 106%, 109%) to prevent throttling with overvolting

-view GPU memory timings