[jandrese]

Theoretically going with ECC Memory should add about 20% to your memory budget, but due to artificial chipset limitations and "enterprise pricing" it is often more like 500%.

Personally, I've always found this to be very annoying. The only people using non-ECC memory should be Xtreme Gamer type people who don't care about their data and only care about squeezing that last 2% out of their system to land at the top of the penis size chart. Non-ECC should be a feature like liquid N2 cooling.