10 fps is what we call 'playable' and its about what I get (about 14, but same difference)
Its okay, but slow and it'll get choppy every once in a while.
but I have a laptop, so the only thing I can upgrade is the processor...
but here's my specs to gauge off of
2.3Ghz Turion Ultra x2
4 GB ram
Win XP (32 bit so it makes that ram kinda pointless)
ATI HD Radeon 3200 (Dedicated Puma)
And I could be wrong, but I believe that you're right, your processor is good for low detail but that graphics card will need to be replaced