rec.autos.simulators

Intel officially launched the MMX chip here in the US recently and had a
question or two that I want to put to the R.A.S. readers.  Is a 'puter
with the currently overpriced (all Intel stuff is the first few months)
chip worth buying?  er...of course it is (just for the sake of
technological coolness), but would it specifically be worth buying for the
games ICR2 and GP2.  Would those games run any better?  Does the software
have to be specifically written to take advantage of the capabilities of
this new wonder chip?

I remember some of these discussion a couple of months ago, but can't
recall if a consensus was made.  Thanks in advance......bjl

The price difference between an MMX and Classic Pentium is quite
minimal (less than $100 for the P200's).  According to reports, when
running non-MMX apps these chips are about 10-15% faster than an
identically clocked Pentium Classic.  This is due to the larger L1
cache, more write buffers, and other architectural improvements.  With
MMX-enabled apps, they can be as much as 50-60% faster.  I should have
mine on Friday, so I'll keep everyone posted with the results.

--

Emory University Graduate School of Arts & Sciences
The IWCCCARS Project: Q & A Representative
Nascar Setups Page: http://userwww.service.emory.edu/~ebusch/

Regards

Marcus

My system won't arrive till Jan 24. How did you get your system so fast?

Joe Cacciatore
http://ourworld.compuserve.com/homepages/jocatch/

MMX has to be actively used by the software. Does the existing software
like ICR2 or GP2 make use of it? No. But considering how quickly ICR2
was ported to use the Verite 3D chipset, I wouldn't doubt that they can
port another version of ICR2 to use MMX quite quickly too.

                                                Yousuf Khan

I didn't get a new system, just a MB, SDRAM, and CPU.  I got the MB and
memory yesterday, and the CPU should be here tomorrow morning.

--

Emory University Graduate School of Arts & Sciences
The IWCCCARS Project: Q & A Representative
Nascar Setups Page: http://userwww.service.emory.edu/~ebusch/

fast?

Those 'transparent performance improvements' are exactly why, even with
non-MMX apps, the P55C is 10-15% faster than the Pentium Classic.
Aside from the 57 new CPU instructions, the changes in the P55Cs
include:

?doubling of the L1 caches, 16kB data and 16 kB instruction cache
?doubling of the Write Buffers, now 4 instead of 2
?new branch prediction unit, taken from the Pentium Pro
?implementation of a Return Stack, as known from the Cyrix/IBM 6x86
?increase of the Pipelines by one step
?improvement of the Parallel Processing Ability of the two pipelines
?ability to pair up two MMX instructions in one go, hence 2 SIMD
instructions can be processed with 16 byte data in one clock cycle

--

Emory University Graduate School of Arts & Sciences
The IWCCCARS Project: Q & A Representative
Nascar Setups Page: http://userwww.service.emory.edu/~ebusch/

MMX doesn't help at all unless the software takes advantage of it, and
there aren't any DOS games out there that can make use of it right now.
There were apparently a few optimizations in the instruction scheduling
that may give marginal performance improvements.

My advice: If you're buying a new machine and need it right away, go ahead
and pay the extra bucks for MMX. If you're thinking of upgrading, hold off
for a few months. Intel announces new prices every quarter and they nearly
always go down. I would particularly stay away from the Klamath chips until
towards the end of the year, because the current chipsets do not support
SDRAM and other advanced features.

Dave Sparks
IWCCCARS Project: http://www.theuspits.com/iwcccars/index.html
Late Night League: http://www.sequoia-dev.com/Hawaii/latenite.html
Hawaii Handle: davids

Current reports speak about a 10% speed gain for non-dedicated software (result
of bigger cache etc..) and up to 60% for dedicated code which makes use of
additional registers and instructions.

GP2 wasn't programmed specifically for MMX. As far as I know, neither did ICR2.

Of course, this comes from Intel so don't blame me when the performance gain is
an exageration! :-)

Jo
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
When everything else failed, we can still become im-
mortal by making an enormous blunder....

                             John Kenneth Galbraith
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

On the contrary, MMX _DOES_ help, even if the software isn't
especially written to take advantage of it. Changes in the
architecture of the CPU will yield a 15% or so increase in speed even
in normal applications.

Cheers!
John