My understanding is that ECC RAM is slower than non-ECC RAM, even at identical speeds, for the sake that it has an extra 'error check'. As gamers [especially multiboxers] we want the fastest RAM we can get our hands on so there will probably be some sort of performance hit with ECC. Servers and what-not use ECC RAM because downtime = bad and that extra 'error check' helps save on possible downtime. Someone please correct me if I'm wrong.