To the OP, but what is your concern about a heavy activity on the machine?
Core shutdown can be fixed with a CoolBook, I don't know about Rev B though.
On Rev A HDD, I've installed and tuned a Gentoo (a Linux distro that does full compilation of everything) on a VMWare Fusion and that just worked like it should. I kept it to use only a single core most of the time not to take every CPU resource out of the host OS not to slow down everything though.
That took more than a few hours on the initial post install system upgrade.
On the other hand, trying to watch Blu Ray on a boot camp actually failed. PowerDVD couldn't just open it saying GPU is incompatible for Blu Ray, trying to open the movie file directly by SMPlayer or VLC just made it like a slideshow.
Also played EvE (space MMORPG game) but while it did load and play somewhat, didn't get a decent FPS, especially in busy areas. Probably much better on SSD/Rev B though.
But none of them did anything beyond being slow.