Windows XP: about 2.5GB
HL2: 4.5GB
F.E.A.R.: 3GB
Far Cry: 4GB
COD2: 4.5GB
BF2: 2.5GB (+1.5GB for expansion)
Source: ?
Total: 22.5 That leaves about 9GB (minus whatever source takes) for other stuff.
If you install some things on the other Hard drive, it wont be that big of a cut in load times. I can load any BF2 map before everyone on that server except about 2-3 peeps. I spawn before about 60 people each time the maps are switched.
. Thats on a 7200RPM SATAII drive. You can install some games dont take as long to load on the second drive, like COD2 or Source.