360:
Processor: 3.2Ghz Tri-core PowerPC (Not sure why they took a PowerPC processor...)
RAM: 512Mb GDDR3 @ 700Mhz
GPU: ATI Xenos (Which is the equivalent of a ATI Radeon 1800XT-ish, maybe a little more powerful but not hugely)
PS3:
Processor: 3.2Ghz x8 Cell Processor (technically x7 since one of them is only used in case another fails. Also there is and won't be a PC equivalent for a little while.)
RAM: 256Mb GDDR3 @ 700Mhz + 256Mb "XDR" @3.2Ghz (Search up what the XDR Ram is because I don't really understand it myself.)
GPU: Nvidia RSX (Which is the equivalent to an Nvidia 7800GTX.)
Pretty bad if you know a lot about pcs. But take into thought that they have no formal operating system and have no background program's running.