Counter-Strike: Source - System Requirements

Operating System: MacOS X 10.6.6 or higher
Processor (CPU): Intel® Core i3 Processor (2GHz or better)
Memory (RAM): 4 GB RAM
Graphics Card: ATI Radeon HD 2400 or better / NVIDIA 8600M or better
Hard Drive: 10 GB HD space

Minimum: OS X Snow Leopard 10.6.3, 1GB RAM, 4GB Hard Drive Space,NVIDIA GeForce 8 or higher, ATI X1600 or higher, or Intel HD 3000 or higher Mouse, Keyboard, Internet Connection

Operating System: 10.12 (Sierra)
CPU Processor: Intel i3 (Dual-Core)
CPU Speed: 2.2GHz
Memory (RAM): 4 GB RAM
Hard Disk Space: 13 GB
Video Card (ATI): Radeon HD 4850
Video Card (NVidia): Geforce 640M
Video Card (Intel): Iris
Video Memory (VRam): 512 MB
Peripherals: Macintosh mouse and keyboard
IMPORTANT NOTICE: Currently, MW2 for Mac may not be accessible to users in Russia, Poland, and Japan
NOTICE: The following video chipsets are unsupported for Call of Duty®: Modern Warfare® 2:
•ATI RADEON HD 2000 Series
•ATI RADEON HD 6490M, 6630M, 3870
•NVIDIA 9000 Series
•NVIDIA 320M, 330M
•Intel HD 3000, 4000, 5000
NOTICE: This game is not supported on volumes formatted as Mac OS Extended (Case Sensitive)

Minimum: OS X version Leopard 10.5.8, Snow Leopard 10.6.3, 1GB RAM, NVIDIA GeForce 8 or higher, ATI X1600 or higher, or Intel HD 3000 or higher Mouse, Keyboard, Internet Connection

Operating System: OS X version Leopard 10.5.8, Snow Leopard 10.6.3, or later.
Processor (CPU): Intel Mac
Memory (RAM): 512 MB RAM
Graphics Card: Nvidia or ATI GPU (Intel GPUs unsupported)
Hard Drive: 2 GB free hard drive space