Anders, I would really recommend a new system instead of
upgrading a system that's at the end of its life. You may
see it as saving money, but it is only delaying an
inevitable upgrade, and then you have sunk money into an old
machine and will still have to purchase a new machine
eventually. Not to mention that having two machines is a
huge speed up for any workflow, you can have one box
rendering or encoding while you work away on the other.
That said: I think 120 gb should be enough for a cache for the
kinds of projects you have described. Instead of buying a 250,
I'd spend the money on a second drive and run them in raid 0.
This nearly doubles your I/O speeds. The only drawback is if
one drive fails you lose the info on both. However if you are
using it mainly for cache and temp projects, and back up the
info to your main hdd that shouldn't be an issue.
The speed difference between a core i7 930 and the 3770k is
immense. We are talking about nearly a 100% boost in render
speed from the cpu upgrade alone...
