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Old June 29, 2008, 11:41 AM
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vinister vinister is offline
Join Date: Feb 2008
Location: Vancouver
Posts: 297
Default clocking and crashing and gaming and folding and crashing

What causes a GPU to crash? I'm experiencing strange stability/instability, just looking for comments/opinions.

card is a 3870, volt-modded, watercooled.

Stock: 800/1200, 1.35v - runs everything I throw at it except GRID.

F@H GPU client: 998/1340, 1.45v (2 weeks solid, stable)

GRID (game): 740mhz/1200mhz, 1.45v (stock speeds crash in less than 1 second of gameplay)

How come the card can cope with such high overclocks running the F@H client, which uses 95% of the GPU consistently, but when gaming I cannot get near these speeds? I am using GRID as a game example because it is so sensitive to clock speeds. I cannot run the game at the 3870's stock speed, it crashes instantly. Reduce the clocks by 60mhz, and the game will run all day. No amount of extra voltage helped it run at stock speeds, I tried up to 1.55 volts.

I checked the useage and while running grid, the gpu sometimes gets used 100%, but usually is below 80% while the CPU is pegged. While folding, the GPU is over 95% all the time, and the card really heats up, especially at 1Ghz and 1.5v. Why isn't this making the card crash, considering I cant really run any games at this clock speed?

Why is running a game so hard on a GPU compared to folding?
Mobo: DFI 790X-M2R
Proc: AMD PHENOM X3 720
Ram: OCZ Platinum 2X 2GB @ 1066
VIDEO: 3 x Visiontek HD3870
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