Use top, system monitors and free to watch the memory and disk utilization when running Mathematica 8.
I’d think it’s going as good as it gets on the AMD X4 3.4Ghz.
Mathematica 8 is cpu, math coprocessor intensive not disk or memory utilizers.
Otherwise a 60G swap sounds excessive, I’d allocate the most of the SSD to the DB-indices to speed up database access.
The command “free” will show how much total memory is utilized including swap is used during processing.
My guess, windows is disk intensive so its paging file and system files would do well on the SSD as C:/ 60Gb.