Para el que no quiera una cosa tan "techie", ahi va un homenaje al copy&paste con datos más generales:
Playstation 2
CPU: 128 Bit "Emotion Engine"
System Clock: 300 MHz
System Memory: 32 MB Direct Rambus
Memory Bus Bandwidth: 3.2 GB per second
Co-Processor: FPU (FPMA x 1, FPD x 1)
Vector Units: VU0 and VU1 (FPA x 9, FPD x 1)
Floating Point Performance: 6.2 GFLOPS
3D CG GT: 66 million Polygons Per Second
Compressed Image Decoder: MPEG2
Graphics: "Graphics Synthesizer"
Gamecube
CPU: IBM PowerPC Gekko, 128bit, 405MHz
Graphic Processor: Flipper 128bit, 202.5MHz
Main RAM: 24Mb
Graphic RAM: 16Mb
Memory bandwith: 3.2Gb/sec
Theoretical performance: 12million polygons/second
Estimated Real performance: 6-12million polygons/second
Xbox
CPU: P3 733MHz with SSE
Graphics Processor: 250Mhz nVIDIA X-Chip
Total Memory: 64MB
Memory Bandwidth: 6.4Gb/sec
Polygon Performance: 125million/sec
Audio: 3D Audio Processor
Network: 10/100Mbps Ethernet
Media: 2-5x DVD, Hard disk 10GB
No estoy muy seguro de la veracidad de ciertos datos, pero está bien para que te hagas una idea.