Hi, Trying to trouble shoot some memory/hardware issues running memtestosx in single user mode. Obviously it's easier to troubleshoot memory problems if I do it one stick at a time - so is it OK to run only one stick of 8GB ECC (Registered... i have some unregistered I can test too) and test like that? I've tried putting in one stick and OSX boots and performs normally, sees the 8GB of ram. When booting in single user mode and running memtest though, the last 5 sticks have all caused a kernel panic/frozen/thrown an error, so I'm wondering if it's problem with only having one stick? 5 out of 8 sticks having a fault seems a bit suspicious, although it's possible - the RAM is second hand. I'm testing the 6th stick now... Cheers, Ed --- Post Merged, Mar 4, 2017 --- 6th stick crashed... so either the board/cpus (it's a dual 6-core 3.46) is broken, or the ram shouldn't be run with just one stick - at least not for memtest. Anyone able to shed any light?