I am using a Compaq workstation at school that uses ECC RAM and it boots comparable to the other comps (non ECC Dells) which have the same amount of RAM and I dont notice a difference but of course that could be because this one is an old P4(1.8Ghz) while they are P3s. But it isnt too much slower than the newer Dells (using P4 3Ghz) so i doubt ECC RAM will make a 5-10 second difference in boot time. ECC RAM is usually for workstations that rely on not crashing and full stability.