ECC is pricey and not fast enough. All computers, even running at stock, MAY generate an error sometime. They are not gurenteed to though. If I build 10 stock computers today, hook each one up to a UPS, and let them run P95 for 10 years I am sure at least one of them would come up with an error eventually. However, I am also sure that at least of them would pass every test and never generate an error, ever. Thats what computers are designed to do, theyre stupid machines but 1+1 always equals 2.
Us overclockers are of a different breed. We are constantly tracing a thin line between stability and blue screens. Each one of us has a different idea of what constitutes stable. I'm sure there are people out there that don't mind if they desktop out of games after a couple hours, as long as they can get every possible FPS.
The way I see it I want to run 2 outlook windows, 8 IE pages, 6 spread sheets, 10 word docs, 6 adobe docs, 5 visio diagrams, and a pleathora of other misc programs. If I crash from doing all of that I don't want to have to guess: well could that be my memory, cpu, cooling etc. I want to be as sure as possible that my system is as stable as possible. Like I said, we each have our own definition of stable.
Honestly different definitions of stable had never occured to me until I started this thread. If your computer is having unaceptable stability issues that don't show up under stress testing, it might just mean you have to stress more in order for that unstability to show itself.