The second generation Intel Core processor family codename Sandy Bridge introduced Intel Advanced Vector Extensions, known as Intel AVX. Intel AVX is a 256 bit instruction set extension to Intel SSE that requires explicit operating system support. The recently launched Service Pack 1 adds Intel AVX support for Windows 7 and Windows Server 2008 R2.Sandy Bridge brought Intel AVX, another SIMD (short for Single Instruction Multiple Data) instruction set. Intel AVX includes extensions to both instruction and register sets. Floating point intensive applications can take advantage of the new 256 bit instructions and registers to process more data in less time.

Intel AVX introduces a new 256 bit YMM register file, and therefore, the operating system has to add support for YMM state management between context switches. The operating system has to save and restore the Intel AVX state by using xsave and xrstor. xsave and xrstor manage the existing and future processor extended states in the x86 architecture.

Windows 7 SP1 and Windows Server 2008 R2 SP1 added the necessary state management to support Intel AVX. In addition, the XState functions allow applications to access and manipulate the extended processor feature information and state when necessary. If you want to work with Intel AVX, you should install SP1.

If you are also interested in taking advantage of Intel AVX in Linux, you should check that the kernel version is 2.6.30 or higher. This kernel version added support for the necessary YMM state management. MeeGo 1.1 is based on the Linux kernel version 2.6.35; therefore, you can work with Intel AVX without installing additional patches or updates.

You can download Windows 7 and Windows Server 2008 R2 Service Pack 1 from Microsoft Download Center

You can find more information about Intel AVX here

Stan Melax wrote a very interesting article about 3D vector normalization using 256 bit Intel AVX instructions.