mykebrian :
ok, just tell me how you ruined your graphic cards and you'll know
What? They were each running fine for 2-3 years, then they stopped working. They were never overclocked, I didn't even touch them. They just died. First one the fan stopped spinning so card was overheating and system was crashing. The second just stopped outputting a signal to the monitor. The third was faulty but working for a couple of months (games became ultra blurry when MSAA was enabled) and then completely stopped outputting a signal.
Each card died within a few months of the warranty expiring. So if you upgrade every year anyway or every two years, wouldn't be an issue. But if you want it to last longer than the warranty, that's where I had problems. Obviously not everyone has problems or nobody would buy Sapphires any more. But I've owned three and all three died. With absolutely no overclocking, not even touched.