These are the specs for CoD 2 :
Call of Duty® 2
Platforms: MAC
Genre: Action/Adventure
ESRB: Teen
MAC Release Date: May 2006
Operating System: Mac OS X 10.3.9 or later
CPU Processor: PowerPC G5 or Intel chipset
CPU Speed: 1.8 GHz or faster
Memory: 512 MB or higher
Hard Disk Space: 4.0 GB free disk space
Video Card (ATI): Radeon 9600
Video Card (NVidia): GeForce FX 5200
Video Memory (VRam): 64 MB or higher
Multiplayer: Internet (TCP/IP) and LAN (TCP/IP) play supported. Internet play requires broadband connection.
Media Required: DVD Drive
Supported Video cards:
NVIDIA GeForce 5200, 6600, 6800, 7800
ATI Radeon 9600, 9650, 9700, 9800, X600, X800, X850, X1600
Recommended System Requirements:
Call of Duty 2 runs best on a Power Mac G5 or Intel 2.0 GHz or faster
Operating System: Mac OS X 10.4.5 or later
CPU Processor: PowerPC G5 or Intel chipset
CPU Speed: 2.0 GHz or faster
Video RAM: 128 MB
Note that the recommended specs dont mention RAM - thus I would assume at least 1GB would be needed