[geeks] value of PIII PC servers

[Charles Shannon Hendrix]

Fri, 23 Jun 2006 @ 17:54 -0400, nate at portents.com said:

> Well, in theory.  x86 64-bit (aka x64) doubles the register count, and
> makes SSE2 mandatory, dropping the old x86 floating point altogether.  

You also lose MMX, and 3DNow.

In 64-bit mode you use SSE, SSE2, and soon SSE3.

Further, in 64-bit mode you do not waste time saving FPU context because
it no longer has to switch between SIMD and FPU operations.

Personally, I think a new FPU and a seperate SIMD section would have
been a better idea.  A big problem with the old method was the FPU had
to do both jobs, and couldn't do them at the same time.

A seperate redesigned FPU would be nice to have for times when SIMD
isn't your best bet.

Then again, maybe we'll all learn to use it and not care.  Who knows.

Also, despite the improvements, I still think the 64-bit x86 ISA sucks.
But, it seems to inhale with less force now.

We better get used to it... everything else seems to be dying.

> So code compiled for x64 can take advantage of a more sane number of
> registers and SSE2, which isn't bad SIMD.

I don't believe you can get the new registers from 32-bit mode.

>From what I've read, you can do a lot of K8 core optimizations from
32-bit mode OS, but not the full register set.

I'd love to be able to recompile some register starved code if I could
make that happen.

> Unless a person is willing to memorize lists of letter-number
> combinations and what they actually correlate to in terms of GPU
> architecture, graphics memory architecture, and how they correlate to
> real-world quality and performance in both a theoretical and practical
> sense to both OpenGL and DirectX, then buying a video card is the
> equivalent of playing slots.  That part of the industry has kind of
> gone off the rails.

I usually find that getting cards from Asus just works.  Likewise I have
good luck with MSI video cards.

The rest seems a crapshoot, and brands like BFG sell overclocked cards.

-- 
shannon "AT" widomaker.com -- ["I want this Perl software checked for
viruses.  Use Norton Antivirus." -- Charlie Kirkpatrick]