I got this from eidos forums, posted by a moderator

Official System requirements for 'Lara Croft Tomb Raider: Angel of Darkness' from Core Design, although as you can appreciate at this early stage, are subject to change.

Minimum: (Not Finalised)

CPU: 500 Mhz 80x86 Processor (Intel, AMD, Cyrix, etc.)

Gfx: 100% TnL hardware accelerated DX8.1 cards.

Sfx:

HD: 100Mb

OS: Win98 (Win95 is not supported)

Mem: 128 Mb



Recommended:

CPU: PIII 1 Ghz or Athlon 1 Ghz, SSE support

Gfx: 100% TnL hardware accelerated DX8.1 cards.

Sfx: 100% 3D hardware accelerated card with EAX2 support.

HD: 100Mb

OS: Win2K/XP

Mem: 128 Mb

Thanks to Andrew Thompson of Core Design Ltd for supplying this data.