Huh - this is strange. I got my black MacBook up and running with Mojave last night, and my T7500 just started having random freezes and black screens CPU/RAM usage isn't that high (and hasn't been for the last few weeks), sitting at 8-10% and 65% maximum respectively. GPU hasn't been used heavily either (unless displaying the Windows desktop and a few videos is considered intense). I'll have to see if I can troubleshoot it before I go out today...