A PS3 GPU is roughly equivalent to the 7800GT.
But it would need probably at least a 8800GT as PC games are generally less optimized.
Consoles are easy to use and newb-friendly. SCREW THEM>>.
The CPU would be along an Athlon X4.
Sony CPU is pretty competent and that why it costs too much and used to give Sony a loss hen selling their consoles.
I don't know much about the RAM, But fro a PC is would be 4GB