Microsoft XBOX and Nintendo GameCube Specifications:

Please note that I’ve gone to a lot of trouble to get these specifications accurate. Even so I may have made a slip up somewhere (Stranger things have happened, you know!) so please inform me, and I’ll look into it!
 
XBOX:
GameCube:
CPU:
Intel Pentium 3 — 733MHz

IBM Power PC “Gekko” — 485 MHz, 13 Giga FLOPS (peak).

1.3GB per second bus bandwidth.

256 KB Level 2 cache memory
Graphics:

250 MHz customised nVidia GeForce 3 “XGPU” — 140 Giga FLOPS

(4 simultaneous textures)

“Infinite FX”, texture mapping, bump mapping, fog, FSAA, mip-mapping, bilinear filtering, trilinear filtering, anisotropic filtering, real time hard ware texture compression, spherical (environment) mapping.

ATI 162 MHz “Flipper”

Texture mapping, bump mapping, fog, subpixel anti-aliasing, alpha blending, 8 hardware lights, “Virtual Texture Design,” multi-texturing, environment mapping, mip-mapping, bilinear filtering, trilinear filtering, anisotropic filtering, real-time hardware supported texture compression, “HW 3-line deflickering filter (?)”
Polygons Per Second:
Supposedly 125 000 000
6 000 000 - 12 000 000 (May even be over 32 000 000 in terms of maximum performance.)
Maximum Resolution:
1920 × 1080
Currently unknown
Fill Rate:
No Texture: 4 Giga Pixels per second,
1 Texture: 4 Giga Pixels per second,
2 Textures: 4.8 Giga Pixels Per Second
?
Colours:
16 777 216
16 777 216
Texture Compression:
6:1
6:1
RAM:
64 MB — 200 MHz DDR type.
40 MB (24 MB 1T-SRAM + 16MB 100 MHz D-RAM for audio)
Video RAM:
The system RAM is unified with video also.
?
Memory Bandwidth:
6.4 GB per second
2.6 GB per second
Sound:

256 channels (64 3D channels)

“Dolby Digital 5.1” Surround Sound
Customised 101.25 MHz Macronix 16-bit DSP, 64 channels
Operating System:
Customised Windows 2000
?
Backup Memory:
8 GB hard disk drive and 8 MB memory card
Memory Card 59 & other variations.
(59 blocks in 512 KB)
Modem:
None. Has an internal Ethernet adaptor.
56 kb per second type (Optional broadband upgrade)
Supported Software:
XBOX DVD, CD & DVD (with adaptor)
GameCube (Matsushita) 1.5 GB 8 cm disc (DVD movie support on Panasonic version)
Disc Drive
2 - 5 × speed DVD ROM
Some kinda speed DVD drive (8 cm discs only)
Control Pad Ports:
4
4

(The majority of GameCube specifications are official from Nintendo.)