So as not to derail the 100 C thread, I decided to make a new thread. This Apple discussion board topic was linked to that outlines several methods to peg the CPU. In Terminal: Code: $ yes > /dev/null (Repeat to start a second identical process) Code: $ echo 'scale=10000;4*a(1);' |time bc -l -q & (Again, repeat to start another process. This calculates the value of pi to 10,000 decimal places) Code: $ openssl speed & (You know what to do ; this does openssl speed calculations) Just quit terminal to kill these processes. The first one barely made my MBP 5,1 break a sweat (relatively speaking!). CPU temp peaked at around 85 C with the fans remaining as per my SMC fan control settings at ~4300 rpm. The pi calculation was considerable more intensive, with the core temp reaching 95 C before the fans ramped up to full blast. Openssl behaved pretty much the same. How does this work on the 2010 MBPs? Thanks!!