I've tested yesterday a little bit with my system, and just for fun i tested an "impossible" configuration.
In the Bios i set the FSB at 700Mhz and the multi at 8 (maximum for my E2140). Then i've restarted the system and the system boots....

But after detecting the hdds the systems stops.

Here my components:

Intel Dualcore E2140
DFI Infinity 965-S Dark
2*1024MB DDR2-533 Crucial Value Micron D9
Medion X740XL
Coba 650W PSU

Here a video of this action:

http://rapidshare.com/files/38016995/SA400274.AVI.html

700*8