memtest for me is at least 2 passes, but I tend to go right to the ponit where there are errors, and then back off a bit. prime/linX, maybe 8 hours.
Even so, BF3, seems a better stabiltiy test than both, and I like to try SuperPi32M first thing, before prime/LinX.
I also check for page faults in the performance monitor. Proper settings should see near 0 is not nil page faults.(suggests timing issues rather than stability might be an issue sometimes).
When done, all that(which takes just a few hours), then it's an overnight memtest.
I'll be testing all CAS settings, timings, other platforms, etc. Once the review is posted, I can go into fine detail.