Intel® Streaming SIMD Extensions Technology Defined

Last Reviewed: 19-Apr-2016
Article ID: 000005779

What are Intel® Streaming SIMD Extensions?

  • SSE is short for Streaming SIMD Extensions 
  • SIMD is short for Single Instruction Multiple Data

Streaming SIMD Extensions (SSE)
SSE is a processor technology that enables single instruction multiple data. Older processors only processed a single data element per instruction. SSE enables the instruction to handle multiple data elements. It is used in intensive applications, such as 3D graphics, for faster processing.

SSE was designed to replace MMX™ Technology. It has expanded over the generations of Intel® Processors to include SSE2, SSE3/SSE3S, and SSE4. Each iteration has brought new instructions and increased performance.

Streaming SIMD Extensions 2 (SSE2)
SSE2 extends the MMX Technology and SSE technology with the addition of 144 instructions that deliver performance increases across a broad range of applications. The SIMD integer instructions introduced with MMX technology have been extended from 64 to 128 bits, doubling the effective execution rate of SIMD integer type operations.

Double-precision floating point SIMD instructions allow for two floating-point operations to be simultaneously executed in the SIMD format This support for double-precision operations helps accelerate content creation, financial, engineering, and scientific applications.

Original SSE instructions have also been enhanced to support a flexible and higher dynamic range of computational power by supporting arithmetic operations on multiple data types (e.g., double words and quad words). SSE2 instructions allow software developers to have maximum flexibility to implement algorithms and provide performance enhancements when running software such as MPEG-2, MP3, 3D graphics, and more.

Streaming SIMD Extensions 3 (SSE3)
The launch of 90 nm process-based Intel® Pentium® 4 Processor introduces the Streaming SIMD Extensions 3 (SSE3), which includes 13 more SIMD instructions than SSE2. The 13 new instructions are primarily designed to improve thread synchronization and specific application areas such as media and gaming.

Streaming SIMD Extensions 4 (SSE4)
SSE4 consists of 54 instructions. A subset consisting of 47 instructions, referred to as SSE4.1 in Intel documentation, is available in Penryn. SSE4.2, a second subset consisting of the 7 remaining instructions, is first available in the Nehalem-based Intel® Core™ i7 Processor. Intel credits feedback from developers as playing an important role in the development of the instruction set.