The architectures currently supported by the DRI have grown from the initial Intel i386 systems to now include the Alpha Processor and the Sun SPARC machines.
Intel's SSE (a.k.a. Katmai) instructions are used in optimized vertex transformation functions in Mesa-based drivers. This requires a recent Linux kernel both at compile and runtime. See the DRI Compile Guide for compile-time requirements. At runtime a check is made to determine if the CPU can execute SSE instructions. They're disabled otherwise.
AMD's 3DNow! instructions are also used in optimized vertex transformation functions in the Mesa-based DRI drivers. 3DNow! is supported in most versions of Linux. Like the SSE optimizations, a runtime check is made to determine if the CPU can execute 3DNow! instructions.
Alpha-based systems can use Compaq's optimized math library for improved 3D performance. See the DRI Compilation Guide for details.
XFree86 4.0 (or later versions) includes 3D acceleration for the following graphics hardware:
Support for other hardware is underway. Most of the DRI development work is funded by contracts with IHVs. These contracts often prevent us from announcing drivers before they're released. Queries about upcoming drivers may not be answerable.