I checked out an old PC - Core 2 quad. About 2 minutes of Memtest and the
CPU fan is going full scream. After 5 minutes, the heat sink is hot to
touch, so I turned it off. I believe Memtest only uses 1 core??
The heatsink is not clogged with dust, and it is a HP craputer, with
BIOS that doesn't enable overclocking.