For ATI

ATI Radeon™ HD 6990
  • 5xxx/6xxx/7xxx ATI Video Card, or newer
  • ATI Driver v12.8 driver or newer
  • Windows operating system, XP or newer

Note that only 5xxx GPUs and newer are supported due to ATI dropping support for the Brook programming language. They have since moved to OpenCL, which is not supported on 3xxx-class GPUs, and the 4xxx series is not supported enough for efficient FAH calculations. See this blog post for more information.