machine load extreme peaking for short periods....mouse not moving etc.

[compdoc]

>>> believe this is still happening. Admittedly, 4GB on a 64bit machine 
>>> is theoretically not much better than 2GB on a 32bit machine, but

4GB is more than enough for 64bit. I think 2GB is fine for average use, but
4GB costs the same these days. I build systems with 2GB and 64bit with no
issues at all. 

Did you do a fresh install or an upgrade? Did you activate any of the
Proprietary drivers?