So I got a Thermalright SI-97A heatsink. If you haven't seen one of these, they look like an aluminum Star Trek vessel. Adding a 92mm fan to it, and the temperature under load is at 52°C. This isn't really an accomplishment (OOH! 6 Degrees!), unless I can crank the CPU fan down to a bare minimum. This means fan controllers I don't have yet, but which are easy to obtain.
Then I thought, "I need to stress-test the computer, and start thermal cycling". Then I remembered that I run Gentoo, and promptly opened a terminal window and typed emerge -u world.