SSE2 - SSE4.2 Compatibility

I am considering the purchase of some software (AutoCAD) that requires the CPU to support SSE2.

My PC's CPU is an Intel® Core™ i5-650 Processor, which supports SSE4.2.

Basically what I am wondering is whether SSE4.2 is simply a newer version of SSE2, and if so are newer versions of SSE backwards compatible?

2 Answers

For Intel, CPUs that support SSE instructions have always been backwards compatible. It may not be true in the future though.

As a little extra info you can use the program CPU-Z to give you information on what your processor supports. Under "Instructions" will be listed the the extended instruction sets supported.

Most processors that support a higher set such as SSE4 will also support the previous versions, as each instruction set version is likely to build on previous versions.

For example, a model above your processor, note the "SSE(1, 2, 3, 3S, 4.1, 4.2)":