By: Michael S (already5chosen.delete@this.yahoo.com), September 30, 2015 4:24 am
Room: Moderated Discussions
none (none.delete@this.none.com) on September 29, 2015 11:31 pm wrote:
> Tim McCaffrey (timcaffrey.delete@this.aol.com) on September 29, 2015 12:18 pm wrote:
> [...]
> > They cut the performance of MMX instructions in half (compared to Broadwell). They suggest
> > that you use AVX2 instead, except MMX is probably used mostly by 32 bit programs, and I don't
> > think AVX2 is available in 32 bit mode. Not that I think this is a big deal, just interesting.
>
> But AVX2 ins't available on all Skylake CPU, Pentium still don't have it. AVX has been
> first available on Sandy Bridge since early 2011, and has yet to find its way into all of
> Intel CPU, stupid segmentation IMHO.
Stupid segmentation is a part of it.
Another part is Atom still does not support it, not even new Cherry Trail.
In context of usefulness of MMX for new applications it's probably does not matter, since SSE2 already covers majority of MMX functionality. The following SSE extensions, which names I don't care to remember, bring it close to 100%.
> Tim McCaffrey (timcaffrey.delete@this.aol.com) on September 29, 2015 12:18 pm wrote:
> [...]
> > They cut the performance of MMX instructions in half (compared to Broadwell). They suggest
> > that you use AVX2 instead, except MMX is probably used mostly by 32 bit programs, and I don't
> > think AVX2 is available in 32 bit mode. Not that I think this is a big deal, just interesting.
>
> But AVX2 ins't available on all Skylake CPU, Pentium still don't have it. AVX has been
> first available on Sandy Bridge since early 2011, and has yet to find its way into all of
> Intel CPU, stupid segmentation IMHO.
Stupid segmentation is a part of it.
Another part is Atom still does not support it, not even new Cherry Trail.
In context of usefulness of MMX for new applications it's probably does not matter, since SSE2 already covers majority of MMX functionality. The following SSE extensions, which names I don't care to remember, bring it close to 100%.