In order for you to play Call of Duty 4: Modern Warfare on macOS with minimal graphics settings, your computer must meet the following requirements
Supported OS:
10.12 (Sierra)
CPU Processor:
Intel Core 2 Duo (Dual-Core)
CPU Speed:
2.2 GHz
Memory:
1 GB RAM
Hard Disk Space:
8 GB + 1 GB Swap File
Graphics:
NVIDIA Geforce 7300 or better or ATI Radeon X1600
Video Memory:
128 MB VRam
Note:
Intel Integrated GMA 950 and Intel Integrated X3100 are unsupported video chipsets