Pentium Chips: The MMX Files

Paul Bray uncovers the spooky mystery of the Pentium MMX ? the chip that looks like a Pentium Pro but runs faster, costs little extra and suits multimedia applications and games down to the ground

It sounds like one of those supermarket soap-powder challenges. ?Which would you prefer, Mrs Smidgen? A standard 166MHz Pentium PC or one that runs applications up to 400 per cent faster at virtually no extra cost??

Who would expect Mrs S to buy a conventional Pentium after that? Not Intel, it seems. Its Pentium MMX chip, launched on 8 January and the subject of a mass advertising campaign since mid February, is designed to replace the top-end 166MHz and 200MHz Pentium chips, and to form the base specification for PC purchases by the end of the year.

MMX is a souped-up version of the Pentium, designed to run all software a little faster, and multimedia software a lot faster (see box). Businesses could benefit from applications such as video conferencing, multimedia internet access and voice recognition, but MMX is aimed principally at the home market.

?The consumer market is a significant part of the PC market,? says Sharad Gandhi, European marketing manager for multimedia at Intel. ?It is driven by games and multimedia, so we wanted to build these functions into the chip.?

PC makers seem to agree, with several consumer PCs already using the chip. Compaq has based its latest Presario models on MMX chips, and Elonex has been producing only MMX-compatible motherboards for some time.

?I think this will be a natural for a home machine,? says Demetre Cheras, marketing director at Elonex. ?It will be unthinkable to buy a home PC without MMX. I?d probably buy it for my own home.?

Intel is pushing MMX aggressively, with almost no price difference between standard and MMX versions of the Pentium ($407 against $402 for the 166MHz versions, for example). It wants the 166MHz MMX chip to become the base standard by next Christmas, and makes no secret of its desire to manipulate the market.

?If Intel wants something to replace something else on the market, we price it aggressively,? says Gandhi. ?Every 18 months or so, what was at the top of our line ends up at the bottom. We expect that by the end of this year, the 166MHz Pentium MMX chip will be where the 133MHz Pentium is today.?

Again, manufacturers seem to agree. ?I would say that almost definitely MMX will be the norm by the end of this year, if not earlier,? says Cheras.

With chip prices virtually identical, and no special components required, MMX machines could be built as cheaply as non-MMX. In practice, manufacturers may prefer to provide beefier specifications to highlight and support MMX?s higher performance. Compaq?s new Presarios include Sync DRam ? a new type of memory which Compaq claims is up to 15 per cent faster than EDO), as well as faster CD-Rom and hard drives.

Even so, the basic 166MHz Presario sells for under #1,900, and Elonex charges only #50 extra for its MMX machines, compared with those based on standard chips. In the long run, MMX may even reduce hardware costs by making go-faster components like 3D graphics cards unnecessary.

Already dealers and retailers have started to discount their stocks of 166MHz and 200MHz Pentiums. Anyone who still has large inventories of old-style machines could find them hard to sell at their former price.

MMX was first announced last spring, and Intel seems to feel that people who still have large inventories of pre-MMX Pentiums have only themselves to blame.

?People in the channel know demand for MMX is going to go up significantly,? says Gandhi. ?The people who manage their inventory best will succeed. Those who don?t will not.?

If the channel is inured to rapid obsolescence, buyers are not, and Intel made few friends among consumers by launching MMX just after many families had bought new PCs for Christmas.

Intel?s excuses vary depending on who you ask, but in the context of the PC industry?s frenetic pace they seem reasonable enough. Gandhi says the January launch was to please the PC manufacturers, who would have needed a new chip in August or September to have sufficient volume of machines in the shops for the pre-Christmas rush. ?No one wants their product portfolio disturbed in the pre-Christmas season,? he says.

Steve Poole, Intel?s director of European operations, is more prosaic, citing the need to keep Intel?s production lines going, and to keep the pipeline free for future launches.

?We build these big factories and then we try to fill them,? says Poole. ?Had we delayed MMX we would have had to delay further launches.?

But he concedes that the 8 January launch was poorly timed. ?It was an unfortunate juxtaposition of dates,? he says.

If the home market is widely expected to move over quickly to MMX, the business market is a more difficult call. If MMX Pentiums become as cheap as non-MMX, then pretty obviously businesses will cut over ? even if they do not use multimedia software, they would still benefit from the 10 to 15 per cent performance hike which Intel claims for all software.

A Pentium with MMX is still no match for a Pentium Pro, the chip aimed at business power users and optimised for 32-bit software. ?If you?re already thinking Pentium Pro and you?ve already decided on 32-bit and Windows NT, then you won?t change,? says Gandhi.

But an MMX Pentium Pro, code-named Klamath, is scheduled to be launched in the second quarter. Will businesses refrain from buying current Pentium Pro machines and wait for Klamath?

In the main, probably not. Unless they use niche multimedia applications such as video conferencing or voice-recognition, business power users will have less to gain from MMX, and are less likely to deny themselves the speed benefits of buying a Pentium Pro now.

Although pricing is not yet decided, it is unlikely that Klamath will be the same price as non-MMX Pentium Pro chips. ?It will probably start as a relatively expensive chip going into relatively expensive systems,? says Poole. ?It will be a slower production ramp, because our ability to produce volume output will be slower.?

Nor will Klamath plug straight into existing motherboards, as the MMX Pentium can. Poole thinks it may be the end of the year before it becomes mainstream.

Ultimately, though, MMX is set to take over. ?By 1998, everything we ship will be MMX enabled,? says Poole.

Gandhi says: ?MMX is going to be a part of all our processors, just as floating-point is. If we don?t do that and always keep it as an option, the software community will never write for it. It always writes to the lowest subset.?

Unusually, Intel ensured that software was available by the time the MMX chips were launched. This included a special version of the Ultimate Human Body from Dorling Kindersley, which features full-screen video for the first time. DK says rotation and disassembly of the body have been improved, colours are richer and deeper, and internet link-ups are faster.

Another MMX application is the Space Station Simulator from Maris, based on the designs for Nasa?s new space station. Features made possible by MMX include real-time 3D rendering, 360-degree virtual reality and full-screen video.

Although these titles will not run on non-MMX PCs, most software is likely to run on both MMX and conventional Pentiums, using the MMX instructions if it finds them, so inventory and compatibility should not be a problem.

Microsoft is enthusiastic about MMX, especially for combining multimedia elements over the internet, although for business users it believes 32-bit is likely to be more significant.

The company?s Direct X and Direct 3D technologies are already MMX-enabled and are used in its new games Hellbender and Monster Truck Madness. Picture It also uses MMX technology, including internet capabilities such as remote printing, HTML slideshow and OLE slideshow.

Microsoft also claims a 30 per cent increase in performance for some imaging tasks.

Other existing software, such as Corel Draw 7 and Photopaint, uses a certain amount of MMX-enabled instructions, but future versions will exploit the technology more fully.

What seems pretty certain is that MMX is here to stay. Intel has the marketing muscle to push it to the head of the queue, and is not afraid to use it. Even arch-rival AMD has licensed the technology ? an indication, perhaps, that it is not easy to clone and that Intel is on to a winner.

The bottom line is that MMX seems to offer a better product than the Pentium Pro for the same price. If so, buyers would be mugs not to go for it.

ALL YOU WANTED TO KNOW ABOUT MMX

MMX is not an acronym, says Intel, but if it were it would probably stand for multimedia extensions, which is essentially what it is.

The core of MMX is a set of 57 additional instructions to speed up multimedia software such as video, sound, image processing, animation, voice-recognition, 3D rendering and internet access. These allow operations to be performed in a single instruction cycle, instead of several cycles on a conventional Pentium. Image processing, video compression and 3D rendering, for example, are speeded up by processing groups of up to eight pixels at a time.

Intel claims that still-image processing is up to four times faster with MMX, audio performance is up to twice as fast, and video performance is improved by up to 70 per cent. This only applies to software written specifically to use the MMX instructions. The on-chip cache has been doubled from 16Kb to 32Kb, and general processing capabilities have been beefed up with better branch prediction and more write buffers. This, claims Intel, can improve the performance of all applications (including those not written for MMX) by 10 to 15 per cent.

Pentium processors with MMX are currently available in 166 and 200MHz versions. By pricing them at almost the same level as standard 166MHz and 200MHz Pentiums, Intel is obviously planning to phase out the non-MMX chips, although the 133MHz variant (without MMX) is still popular as a base standard. There are also MMX Pentium chips for portable PCs.

Intel claims the MMX Pentium is a match for a standard Pentium Pro when running 16-bit software. But 32-bit software (for which Pentium Pro is optimised) still runs about 40 per cent faster on a Pentium Pro, claims Intel.

MMX Pentium chips are pin-compatible with a conventional Pentium, and can use the same Bios and other support chips. The only significant difference is that MMX chips run at 2.8 V instead of the 3.3V of a standard Pentium. So MMX machines can only be built using motherboards designed for a standard Pentium chip if the voltage can be reset.

An MMX-optimised motherboard, called 430TX, will be launched soon by Intel.

An MMX Overdrive chip for existing Pentium systems will be available soon, says Intel, possibly as early as March.