Hi so have done that. I did the test running both, I then swapped them around and was still getting errors, I then tried doing one stick at a time and one was able to finish 4 passes without error but the moment I swapped the other one in (the faulty one), I started getting errors immediately. I also tried using different dimm slots at a time and was still only getting errors on the one RAM stick. Currently only running one stick (the working one) and haven't had a single crash yet