Mac OS X v10.6.8 or v10.7. Adobe Creative Suite 5, CS5.5, and CS6 applications support Mac OS X Mountain Lion (v10.8) when installed on Intel based systems.**
1GB of RAM
2GB of available hard-disk space for installation; additional free space required during installation (cannot install on a volume that uses a case-sensitive file system or on removable flash storage devices)
1024x768 (1280x800 recommended) resolution display with 16-bit color and 512MB of VRAM
OpenGL 2.0–capable system
This software will not operate without activation. Broadband Internet connection and registration are required for software activation, validation of subscriptions, and access to online services.† Phone activation is not available.
You might not meet the first one there with some older processors.