Photon wrote:

> Shortly after I responded to the two responses to my posting, I
> randomly, unintentionally, fell upon new information directly related to
> this.
>
> In the Pentium II Deschutes series of processors (P2-333 and up), there
> are two new semi-undocumented instructions.  These instructions are
> primarly meant to be real and documented (people in the know believe...)
> when the MMX2/KNI processors come out (which are the Katmai series).
>
> The instructions are FXSAVE and FXRSTOR, which do the same basic
> function as FSAVE and FRSTOR, except "faster".  Apparently this is
> primarily targeted at OS vendors, to speed up FPU state switching when
> task switching.... but they are also here to make this state switching
> faster for software which makes use of MMX or (sometime soon..) MMX2
> instructions.
>
> The presence of the semi-undocmented instructions can be accurately
> detected via CPUID.
>
> Here's a link to the site I found this on:
>
> http://www.tbcnet.com/~clive
>
> Look around there for the word "Deschutes".
>
> Given these instructions... that lowers the major barriers to one last
> biggy:  Finding some intense non-FP math to accelerate in povray :)
>
> Just htought someone might be interested in this stuff anyways, since we
> were discussing it though...
>
> Brandon

  I heard this too, around the time Deschutes was debuting.  Apparently
Win98 is supposed to make use of them.
Also, was it mentioned that the 3dnow instructions are supported by DirectX
6?  Not that that will matter much, but . . .

Ciao

Willow

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