It's looking more and more like a GMP cpu problem.
@juve4v and @liifer what kind of CPUs do you have in those rigs that crash immediately?
EDIT: @LongAndShort i see now you have the exact same problem. And you said this rig has an i7 3820 right?
Sandy 17 2600k + 290 .I'll try downgrade from 14.4 to 14.3 and report back.