Choosing Your Weapon: Personal Computer Platforms

Article excerpt

When was the last time you thought about your personal computing platform--the hardware and operating system, that is? If you're lucky, it's been awhile--but if it's been more than three years, it's time to review your situation. If you reconsider your operating system every six months, then skip this article: you care a lot more about these issues than I do, and aren't likely to learn much here.

Ideally, your computer is a toolkit, and you don't worry about its basics very often. It's almost always a bad idea to acquire the newest operating system or hardware platform in its first few months on the market, and you're rarely missing too much by being a bit behind the times. Still, once in a while you should consider what the times actually are, and whether you need to move forward.

The discussion that follows is my own sense of the marketplace in early 1997 and where it's likely to go through the rest of this year. I'm no prophet, and there could be significant unexpected developments this year--but most of those won't matter until at least 1998.

INTEL CPUS AND COMPETITORS

Most computers in the world today, and more than 90% of new desktop computers, use central processing units manufactured by Intel. The bulk of new computers come with either Pentium or Pentium Pro CPUs. Outside of specialized workstation, server, and mainframe markets, the only serious competitors to the Pentium and Pentium Pro are the IBM/Apple/Motorola PowerPC-and Pentium-compatible CPUs from AMD, Cyrix, and perhaps others.

For most users, the PowerPC is closely linked to the Mac OS: you probably wouldn't buy a PowerPC-based computer unless you wanted the Mac OS, and you can't run Mac OS on an Intel CPU. But what about Intel and Intel-compatible CPUs?

Through most of 1996, the rule was fairly simple: Pentium for the desktop, Pentium Pro for servers. As the difference in price narrowed, that rule was refined somewhat: Pentium for Windows 95, Pentium Pro for Windows NT. Then, in the fall of 1996, Gateway 2000 began using Pentium Pro CPUs for its midrange and high-end family systems as well as professional systems, all running Windows 95. Other vendors have followed and will follow. The rules are no longer simple.

The Pentium Pro architecture is tuned for 32-bit code, and in early implementations the CPUs were inferior to Pentiums when running 16-bit code. While Windows 95 is mostly 32-bit code, there's still some 16-bit code in the system--and many users still run 16-bit Windows and DOS programs.

Three things have happened to make the Pentium Pro more desirable for regular PCs:

* Recent motherboards and chipsets have improved Pentium Pro performance on 16-bit code.

* Most applications have come out in 32-bit versions, so that people have fewer 16-bit programs as they move to current versions.

* The price differential between Pentium and Pentium Pro chips has almost disappeared, so that a 180MHz Pentium Pro system costs about the same as a similarly-configured 200MHz Pentium system.

That third point is precisely the case for Gateway 2000's family PCs at the end of 1996: $2,499 bought either of two systems that are essentially identical (and very well configured), except that one has a 180MHz Pentium Pro CPU while the other has a 200MHz Pentium. The Pentium system has one remaining edge: it uses SDRAM, significantly faster in some cases than EDO RAM, and so far Pentium Pro motherboards can't use SDRAM.

Which makes more sense? For most users, and particularly those without lots of "legacy" programs (DOS and early windows), the Pentium Pro may be a better buy. It will run pure 32-bit applications much faster and will run older programs just about as fast.

It gets more confusing later this year as Intel adds MMX instructions to the Pentium (but not the Pentium Pro) that speed multimedia applications. Come 1998, MMX should appear in the Pentium Pro as well--and it's likely that the improvement from MMX is as overstated as most of Intel's claims for new processors and enhancements. …