CPU: Athlon 64 3000+/Intel 2.8ghz
Graphics: Nvidia 6200 or ATI X1300 - Shader Model 2.0
RAM: 768MB on Windows XP or 1GB on Windows Vista
HDD: 6GB
Internet: 256k+
Optical Drive: DVD
Software: DX9.0c with Windows XP
Recommended Requirements
CPU: Dual-core CPU (Athlon X2/Pentium D)
Graphics: Nvidia 7600 or ATI X1600 Pro (SM 3.0) or DX10 equivalent
RAM: 1.5GB+
HDD: 6GB
Internet: 512k+ (128k+ upstream)
Optical Drive: DVD
Software: DX9.0c with Windows XP
These are estimates only and are no way official. I just want to makesure that is clear. However, if you have a graphics card similar in performance to, or better than a 7800GTX, then expect to play Crysis quite nicely ( presuming your other system specs are up to scratch ).