Sukhoi, do you have info/stats to back that up?
It was my understanding that ECC delays data transmission for one clock cycle (133MHz DDR - 1 Hz DDR). Not really a huge penalty.
The extreme case I'm living right now is that I bought 512MB of non-ECC PC2100 from Crucial when it first went on sale (I know, could have spent have of what I originally did ... if I had waited for the mobo announcement). Only Tyan has SMP Athlon boards out now (the reason why I bought the DDR) and they all require EEC DDR. So, until someone (Asus) releases their SMP Athlon board that doesn't require ECC DDR, I have to sit tight. Hopefully, the mobo prices will be more inline by then so I woun't be too eager twice.
-SUO