I have a Gainward GTS250 1024MB, and a problem appeared 2 years ago when i was playing Starcraft 2. Sometimes, in game, video "parasites" appeared.
It was like snowing white and blue pixels all over the screen. As if the video cable was very poor quality, or something like electromagnetic interference. When I exit the game, the problem continued in windows (W7 64) and had to restart. No problem after restart.
I thought the game had problems, and didn't give it much thought. I stopped playing SC2 around that time. Continued to play other games in the past 2 years with no problem.
Two days ago I reinstalled SC2, and after a few hours the problem reappeared. I had some mid 2012 drivers for the GPU. Installed the latest drivers (December 2012), and the problem persisted. So I thought, again, that the game has issues...
Cleaned all coolers in the case, reinstalled all new drivers, ran video memory test and 3D Vantage, no errors. But after that, I ran the Windows7 Experience Index benchmark, and at the end of the test, the pixel snowing started again. So now I'm pretty sure that it's not the SC2 game that has problems.
My PSU is Seasonic M12 750W, Intel Q6600, 6GB RAM DDR2. (I know it's an old PC, but it's ok for what i need now)
Okay first of all you need to know the correct term. It's called "artifacts" not "parasites". Close though
What you see is typical for a GPU that gets too hot. Have you tried monitoring the GPU temperature while gaming? Download a monitor software like MSI Afterburner and watch the temperature while you are gaming.
Have you ever overclocked the GPU. these artifacts also appears if you overlock your GPU too much.
The GPU was never overclocked.
The thing that's weird is that I played other games for the last 2 years... (MW, NFS, all night sessions of Diablo3, 12h running HD videos) didn't get the artifacts.
Only SC2 and W7 benchmark managed to over heat my GPU... (if overheating is the issue)
I will try monitoring the GPU temperature while gaming...
Do you suggest removing the GPU heat sink and replace the thermal paste?
Ok. so i have ran Furmark and MSI Kombustor for a few hours, monitored temperature while playing NFS, Diablo3. Temperature never went over 80 Celsius (max was 77 i think) monitored with MSI Afterburner, Gainward ExperTool, and GPUTemp. No problems.
The max temp for GTS250 is about 105 Celsius from what I've read. Never even approached that.
Final test was Starcraft2. Temp, again never went beyond 80 Celsius, but after about 30-45 min, the artifacts appeared.
So now I don't think it's GPU overheating problem... maybe it's not even the GPU... I have no idea whatsoever. Maybe i should ask around SC2 forum for this...
Turning back to say that it may be a a problem with the driver and not the card itself. So don't worry about your card. Stacraft 2 and some of the Nvidia cards are not working that well together apperantly. What settings are you playing at. Turning down shaders from ultra to high has been known to work.
I've uninstalled and deleted the GPU drivers and let w7 install it's own drivers (feb 2012 I think...). Activated vsync in SC2 and ran a few 4v4 AI vs AI games for about 2 hours - all details ultra in 1080p and had no problem. It was ok, but I'm not getting my hopes up just yet, i will test it throughout the next few days, and post the results.
Thank you all for the support.
As a possible conclusion, for me at least, it seems that SC2 is a better stress test for GPU than FurMark or Kombustor. ( just kidding)