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Intel now has a site covering its forthcoming AVX technology (aka post-SSE SIMD). I haven't had a chance to do more than skim the materials yet, but it looks like they've hit the high points: 256bit registers, 3 and 4 operand instructions, FMA and permute/shuffle, etc. There's even some AES instructions in there.

I wonder if they didn't chance the name from SSE to AVX because AMD started to mess around with how SSE normally worked. Meaning there are 2 different versions of SSE4 (SSE4.1 vs SSE4a) and SSE5 would not include items in SSE4.1 or SSE4.2.

Really names aren't that meaning full at that level.

*edit

It does sound like it will be a useful improvement overall, that hasn't always been the case with some of the versions of SSE. Some steps seemed to have very minor impact or at least very targeted usage.

Hi, We made the name changes mainly because we wanted to stress that this is not an incremental enhancement like the industry's seen for the last several years, it encompasses all the old functionality (through SSE4), adds those new goodies you've noted, and gives us a much more efficient way of encoding all floating-point and SIMD operations. We're setting a new direction for the future - so our future enhancements will be derivative from AVX.

We basically needed a compact and efficiently decodable way to encode new features like the distinct source register and the vector length, and wanted some growing room for future (unannounced features), without blowing up the instruction size. The new encoding reclaims 4 old prefixes (REX, 66, F2, F3 - plus that leading 0F byte) with a single prefix called VEX, while preserving the same opcode, modrm, and sib bytes we had before. So we get back all those prefixes (if anyone should want to use them in the future) and the 3-byte VEX payload had 3 unused bits for future exansion.... lots of possibilities.
(Mark Buxton - app perf team @ Intel - new to the forum).

Welcome to the forum

I'm sure the name change was done for a number of reasons, all of them reasonable.
*edit, welcome Mark*

Hello, Mark, and welcome. We certainly appreciate having experts and industry folks joining the forums. Now I know I need to keep my mouth shut until I finish reading the materials.

I don't know if you're aware of it, but there's a discussion of AVX over at RealWorldTech that you might want to contribute to; I'll point you to the root of a couple of the more critical posts but they are by no means universally negative (the RWT forums generally seem to maintain a civil tone and a lot of very knowledgeable people).

Welcome to TR