I picked up an evga sc gts450 last October, and I wanted to try sli, so I ordered another one. I wanted to OC them to save some money and saw that evga has their own oc'ing software. I decided to try it and find a stable speed before the second one came. After reading for a while on various forums, I begin following a sticky on evga's forums. I downloaded ATITool to scan for artifacts, TechPowerUp GPU-Z and evga's precision software. I follow each step as it says and let ATITool run for 5 minutes each time. I started with the FTW speeds, since I know they would be stable. A couple steps after I max out the memory clock, it reads 1020/2040/2280. I let that run for 10 min without any errors, so I loaded Civilization 5 and set everything on High with the resolution to the highest it could be while not in full screen, something by 1050. It didnt last too long before the computer crashed. I restarted it and stepped it down to 1010/2020/2280. I left ATITool run for 10 min with no problems so I load Civ 5 with the same settings as before. I played for two hours without a problem. It didnt look great, but it was better then what I had before. While I was playing I was keeping an eye on the temps and they stayed below 45 the whole time with the fan around 50 the whole time.
The evga program contradicts itself and TPU GPU-Z with the core clock, shader clock, and memory clock speeds. I am assuming the TechPowerUp is, and it runs Civ 5 better.
Just to make sure the speeds were somewhat stable, I ran the ATITool again, but this time for 50 minutes, and no errors. I let it run while I typed this up (another 10 min) and no errors.
My question is, are those speeds possible?
Most Fermi cards are lucky to crack 1ghz but I have even seen a gtx 590 break that but it was modded. 1.1ghz is the limit for any Fermi card except for that one in a few hundred thousand that might be the exception.
Simply put, you are pushing the card far further than it was meant to go, it may run at speeds stable for now, but the extra voltage being pushed through the card will burn it out faster, unless you are manually limiting voltage settings, and holding those high OC's with a second card in the mix makes it more complicated yet again