Worse performance after overclocking GPU?

[OUT FOX EM 10]

I'm trying to squeeze the last drop of performance out of my brother's computer that I can, so I overclocked his CPU and his GPU. I ran all stress/torture tests to make sure the system is stable and that the temperatures are good, so I know that is not a problem.

What IS a problem though is when I overclock his GPU, ArmA II's framerate takes a HUGE hit (up to 50%).

Here's the PC specs:

Intel Q9550 (3.8 GHz)

4 GB Corsair Dominator DDR2 (1066 MHz)

Nvidia GTX 260 216 (740/1586/1650 MHz)

Asus P5E

Windows 7 x64

ArmA II Settings:

Version: 1.05

Visibility: 1600

Quality preference: High

Interface resolution: 1920x1080x32

3D resolution: 1920x1080

Texture detail: Normal

Video memory: Default

Anisotropic filtering: Normal

Antialiasing: Normal

Terrain detail: Normal

Objects detail: Normal

Shadow detail: Normal

Postprocess effects: Low

The odd thing is that when I use RivaTuner to overclock his GPU from 655/1404/1125 to 740/1586/1650, the framerate will go from 60-80 in the menu and 30-45 in the game, to 18-22 in the menu and 15-25 in the game. That's a 50% performance hit.

I know the simple answer is "well then don't overclock it" but that doesn't help me understand why overclocking is killing performance, when it should in fact be just the opposite.

Even odder still is if I use RivaTuner to set the clocks back to the stock factory clocks, my performance suffers just the same. Obviously this is not related to the clocks of the card, but the act of changing the clocks itself. For the record, I tried EVGA Precision and the same thing occurs.

I've monitored the clocks and the temps while in-game and they're normal. The GPU is at 54C under full load in FurMark, and doesn't pass 51 in ArmA II.

If anyone has any experiences like this, or better yet an explanation, why RivaTuner/EVGA Precision would kill performance even at stock clocks I'd love to hear it. Once I solve that problem I should see results from the higher clocks.

[maddogx 13]

So even after reverting to stock clocks the performance is still bad, presumably until you reboot the computer. At least if I understand you correctly. If that is the case, logic dictates that the problem lies somewhere else. Think about it: fresh boot, stock clocks - good FPS. OC, then revert to stock clocks - bad FPS. It doesn't make sense. Therefore the framerate is almost certainly being affected by some other factor.

Somehow, overclocking the GPU is having an additional unwanted effect on your system that you're not seeing, which will probably be hard to troubleshoot. Some questions come to mind:

- Have you tested performance in other games after overclocking, then after reverting to stock clocks? It would be interesting to see if other games are affected in the same way.

- What kind of power supply does the system have?

- You say you've been monitoring clocks and temps while in-game. Have you also been checking the GPU and video memory load? Current versions of the software "GPUz" can do this.

Edited March 22, 2010 by MadDogX

[OUT FOX EM 10]

So even after reverting to stock clocks the performance is still bad, presumably until you reboot the computer. At least if I understand you correctly. If that is the case, logic dictates that the problem lies somewhere else. Think about it: fresh boot, stock clocks - good FPS. OC, then revert to stock clocks - bad FPS. It doesn't make sense. Therefore the framerate is almost certainly being affected by some other factor.

Somehow, overclocking the GPU is having an additional unwanted effect on your system that you're not seeing, which will probably be hard to troubleshoot. Some questions come to mind:

- Have you tested performance in other games after overclocking, then after reverting to stock clocks? It would be interesting to see if other games are affected in the same way.

- What kind of power supply does the system have?

- You say you've been monitoring clocks and temps while in-game. Have you also been checking the GPU and video memory load? Current versions of the software "GPUz" can do this.

Yeah that's about right. If I use RivaTuner (or EVGA Precision) to set the clocks to factory settings, in other words override factory settings with ANY setting -- higher or lower than stock -- then I get the problem. If I never use RivaTuner at all then I don't have the problem.

As for other games, this is a clean install. I haven't really installed much on there other than ArmA II and BF2 (for ProjectReality). PR runs fine either with the overclock or without it. The system uses a Corsair 750w PSU (this one).

Next thing I'll try is overclocking before playing BF2, then reducing back to stock clocks via RivaTuner and see if it makes any difference in there.

[forteh 11]

In past experience Ive noticed very little increase in performance by overclocking the GPU, most gains (especially with arma2) seem to be with cpu speed.

Ive just upgraded to a similar spec* to the one posted in order play arma2 and now have good solid framerates. Running 1600x1200, 100% fillrate, all settings on high apart from shadows on very high, PP on low and AA disabled (1600x1200 on a 19" crt eliminates most aliasing for me anyways) and view distance of 1990.

I get 44fps average on benchmark 1 and restarted harvest red last night, getting a solid 30-35fps on those settings so Im happy. If you need more fps then I would try to push the cpu faster or drop the resolution alittle :)

*i3 530 @4Ghz and windowsXP but the rest is about the same.