Intel MMX and Racin' Sims

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/

> 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 I belive these games will run just a tad faster thanx to a larger L1 cache ( 16k instead of 8k) but they don't use any of the MMX special features - but the again what do i know... Regards Marcus

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>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/

Eric, please do keep us informed. I just ordered last night a new Micron 200 mhz MMX system and I can't wait to see how much faster it is than my current 90 mhz system. As it is now, I have to turn off skid marks, racetrack textures, etc to see a noticable improvement in speed when racing. My system won't arrive till Jan 24. How did you get your system so fast? Joe Cacciatore http://ourworld.compuserve.com/homepages/jocatch/

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> 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?

Yeah, the software has to be specifically written to make use of this additional functionality, it's not transparent performance improvements like better pipelining, more caching, more superscaling, etc. which the software really has no direct control over, but benefits from without knowing about it. 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

>I didn't get a new system, just a MB, SDRAM, and CPU. I got the MB and

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

*REALLY* interested in your comments/observations on this subject. Please ignore ***wits. Many thanks for prior lucidity/info/help. Post Away...cheers...duncan.

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>> 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 >I belive these games will run just a tad faster thanx to a larger L1 >cache ( 16k instead of 8k) but they don't use any of the MMX special >features - but the again what do i know...

Its actually 32k instead of 16k :-)

> Its actually 32k instead of 16k :-) - like I said: what do I know.... :)

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 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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>>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 >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.

My understanding at this point is that there is no additional registers in the cpu for MMX because this would have required modifications to the operating system such as DOS or Windows 95 to support the additional registers. What they did to avoid this was to let MMX "borrow" registers from the floating point unit. This means that the cpu will have to switch between MMX and floating point when either wants access to those registers. At least that's what was posted elsewhere. It was also pointed out in that post that any game or other software using floating point calculations may actually run slower on the MMX such as Quake.

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