What I meant by weak CPUs is that when used it in conjunction with NPM, specifically when using the "plus" option, then there's a problem.  CcminerAlexis78 still has the problem of a long "warmup" time when running more than 3-4 cards, so I'm running 2 copies of NPM, and as much as I like the "plus" option, running 2 instances of that just punishes my CPU (even after the delay increase from 10 to 60s and changing priority to "below normal"), so when HSRminer kicks in while the CPU is already running at 100% causes it to sometimes crash.  I have a friend running the same setup with an i3, he doesn't have this problem.