CPU Multimedia Instructions

[Gamingphreek]

Everyone remembers when MMX came out, and then 3dNow and that. What exactly is all of this doing. Would are computers be considerably slower without it?

Like i said what exactly are they doing?

-Kevin

 

[jhu]

no because very few programs actually use those instructions. about the only useful simd instructions sets are the combination of sse/sse2 combination. sse by itself is fairly useless.

 

[Gamingphreek]

What about MMX and 3dNow! What are they actually doing. Does anything actually take advantage of it? Like i said what are they actually doing... maybe this thread belongs in the Highly Technical

-Kevin

 

[jhu]

the problem with mmx is that the instructions operate on integers only so there is limited use for them. the more important fp operations weren't introduced until 3dnow. unfortunately, there's not much support for those instructions since intel doesn't use this. then came sse, which much like 3dnow, introduced packed fp operations. unfortunately, the major shortcomings to 3dnow/sse is that they were limited to 32-bit fp operations. no one uses 32-bit fp precision (except for that guy over there cowering in the corner). finally sse2 came and brought packed 64-bit fp operations. my question is: why did intel take so long to bring out 64-bit simd? intel should have introduced sse2 at the time sse was introduced. that would have made more sense. sse2 = what sse should have been.