Warning! Speed bumps ahead - Penn Printout, Feb 1997

The University of Pennsylvania's Online Computing Magazine

February 1997 - Volume 13:6

Warning! Speed bumps ahead
By Don Montabana

Experience has taught me to be cautious about what I read in the computing press. While press pundits would have us believe that the future has arrived long ahead of schedule, past encounters with the "future" have taught me to temper my optimism. Let's apply a dose of reality to two current technology darlings of the computing press: 56K modems and the Pentium MMX-class microprocessor.

Up up and 56K away

About a decade ago when modems made the dramatic leap from 2,400 to 9,600 bps we were told that we were at the physical limit of data transmission through telephone -- 9,600 was the end of the line. You blinked. A few years later we began seeing modems with "effective" speeds of 14,400 and 28,800 bps.

Were the phone lines getting faster? Were we finally able to bend some of the laws of physics? The answer was a clear no to both questions. These new "speeds" were made possible by special compression and error correction protocols that made it seem as if the data was indeed moving at those breakneck speeds. Recently, with some additional fine tuning, effective transmission speeds were bumped up to 33,600 bps. It looked, for all intents and purposes, as if we had once again reached the technical limit of data transmission across telephone lines.

You blinked again. In fact, we all blinked. And along came the next speed increment to 56,000 bps. Dubbed x2 technology, the implication was that this technology would provide transmission rates twice as fast as your now "obsolete" 28,800 bps modem -- you remember, the one you bought last month. Now faster is clearly better, and faster is the holy grail we've all been looking for as we surf the web, but does 56K technology deliver?

56K advice

To help separate the hype from the hope, I've drawn together some basic facts to help guide you in making a decision of whether to step up to 56K. The facts suggest that you should wait until the 56K standard is finalized and available from your service provider on their side of the connection, as well as that you should temper any expectation of "effective" 56K speeds.

There are at least four 56K technology "standards" developed or under development. With no single standard in place, there seems little chance of compatibility between the competing manufacturers. By purchasing an early 56K modem you're betting that its "standard" will be the de facto one. If not, you'll either have to hope you can upgrade or simply buy another 56K modem.
Both the carrier and the customer need to have the faster 56K modems to take advantage of any speed increment. To complicate things further, both ends must match, that is, the carrier and the customer modems must support the same, as yet unknown, standard.
Your favorite browser will not work twice as fast for the simple reason that transmission speeds with this new technology are asymmetrical. Although transmission downstream from the carrier to the customer are rated at 56K, data moving upstream to the carrier from the customer are at a maximum speed of 28.8-33.6 Kbps. Keep in mind that these are theoretical values and are possible only in an all-digital network. In the "real" world, 56K modems will be somewhat faster (20-40%), but not twice as fast as 28.8.
Aside from 56K technology, there is the "last mile" problem imposed by the existing telephone service. For a user dialing in from home over a standard analog telephone line at 28.8 or 33.6 Kbps, the connection from the home to the local Central Office is the "last mile" and often consists of older, less interference-resistant wiring that was probably installed in the 70s or earlier. Until this weakest point in your telephone service is upgraded, there is little chance that you will benefit greatly from newer modem technology.

Unless you are a compulsive risk taker who enjoys being on the bleeding edge of a standardless technology, you should wait at least six months following the release of the first 56K modems. There's an old maxim that goes "never invest in version 1.0 of any technology." If you need the additional speed right now, investigate ISDN services. Although considerably more expensive, speeds of up to 128K are possible. (Dan Kegel's web page has a good overview of ISDN services.)

But, get ready to blink again. Just around the corner, new cable modems are approaching. This next generation of modem is capable of Mbps (millions of bits per second) and should be viewed with the same caution as the newborn 56K technology.

What's all the MMX fuss?

In the never ending battle for better, faster, and more impressive microprocessor features, the latest volley fired was the introduction of the Pentium MMX (MultiMedia eXtensions) chip by Intel Corporation. If you are contemplating purchasing a new machine, should you invest the added $150-250 to get the latest and greatest?"

What you get for the added investment depends on what you're looking for. MMX processors are rated at the same speeds (133-200 Mhz) as existing Pentium desktop and laptop systems, but are modestly faster due to a larger (32 Kb vs 16 Kb) built-in memory cache.

What distinguishes MMX series of chips from its plain Pentium branch of the family is the built-in set of hardware and software graphics accelerators. Nearly sixty new multimedia-optimized instructions have been added to the existing instruction set. The expanded instructions combine with a new feature known as SIMD (Single Instruction Multiple Data), in which a single executed instruction can perform the same function on multiple pieces of data.

Bottom line? When used in concert with graphics software written to be MMX-compliant, your multimedia applications will fly! At the beginning of February, very few applications were shipping that were MMX-compliant -- and none of them are supported by ISC. By year's end, it is expected that the new MMX Pentiums will be the dominant flavor of Intel processors in production. (Note: Microsoft recently announced that they will not provide MMX support for their Office 97 application suite.)

Computer models employing the new Pentium MMX chips are shipping now from all the major manufacturers. Contact the Computer Connection at 898-3282 or visit their web site for additional information.

DON MONTABANA is Director, ISC Support-on-Site Services.