I'm certain the memory is not bad as they test by themselves ok. It's just when I have all 6 of them in there I keep getting errors when I run memtest86 on test 6. All other tests pass without problems. When I only use 3 dimms, they can run up to 2133 no problems. It's just when I try to run all 6 of them at 1866 that I get errors on test 6. I did find that upping my tFAW helped most of the errors that I was getting on test 6, but not all of them. I'm just running a 133mhz bclk as I'm just messing around with memory overclocking. I've tried lowering the unclock from 3200 to 3066 without success. I'm down to 2800 (1.5) but have not been able to run it under memtest yet to see if that fixes errors. I'm running 1.35v vvt and 1.66 vdimm. Any help would be great as I can't seem to find anyone that has errors on test 6 on X58 that can tell me what's causing it.