The Cutting Edge: Computing / Technology / Innovation : High-Performance Components, Falling Prices Make This a Good Time to Buy

If you’re thinking about buying a personal computer for your home, you’ve picked a good time. Prices over the next few weeks are expected to reach new lows as computer makers get ready for what looks to be a blockbuster holiday season.

About a third of American homes now have PCs, which means there are still plenty of potential first-time buyers, as well as those looking to replace older machines.

A key reason for the falling prices is the availability of lower-cost, high-performance components. Intel, which has defined the standard for IBM-compatible central processing unit chips, has come out with faster, more energy-efficient and less expensive versions of its Pentium chip (a CPU that can run up to twice as fast as the 66-megahertz 486 DX2, the leading CPU). Aggressive marketing of the Pentium has put downward pressure on 486 prices.

I’ve tested several Pentium-based machines and am now using a Dell XPS P90, which features the 90-MHz version of the Pentium. In terms of raw processing speed, it’s twice as fast as my 66-MHz 486 system--but that extra speed doesn’t show up with most of the programs I run. If you’re buying a new machine for typical business applications such as word processing, spreadsheets and communications, you’ll save about $500 and still get excellent performance by getting a high-end 486 system instead of a Pentium machine.

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If you’re going to buy a Pentium, I recommend the 90-MHz over the 60-MHz version. They are considerably faster and more energy-efficient.

Ironically, my kids and I do notice the Pentium’s extra punch when we’re using drawing and graphics programs and some multimedia CD-ROMs. It’s been a big surprise to the PC industry that home computer users (like my kids) often need more power than office workers, especially if they’re playing a lot of games. But I still think a 486, for most people, represents a better value.

Keep in mind that all 486 CPUs are not equal. Usually there’s another number--such as 33, 50 or 66--that indicates the CPU’s speed in megahertz. The higher the better, but a small difference in speed (say 50 compared to 66) isn’t a big deal. An SX after the number means there’s no math co-processor, which usually isn’t a problem unless you’re a heavy spreadsheet user or plan to use computer-aided design software--or want top performance on one of a handful of games that take advantage of the co-processor.

Some PCs have “Intel Inside” stickers showing there is an Intel-brand CPU. It’s clever marketing, but don’t be afraid of non-Intel CPUs, such as those from AMD and Cyrix. Major manufacturers, including Compaq and IBM, have found these CPUs to be reliable and compatible.

Apple is now shipping Power Macintosh machines with the Power PC CPU. These are very fast, but only if you’re using software designed for this chip. Older Mac programs may actually run a little slower on the PowerMacs than on other models. If you buy an old-style Mac, be sure it’s a model that can be upgraded to the Power PC.

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The CPU isn’t the only chip that helps determine a computer’s speed. The amount of random access memory is very important. Many low-cost home systems come with four megabytes, but that’s not enough if you want maximum performance with Windows or Macintosh software. You’re much better off with eight or more megabytes: An extra four MB should add between $150 and $200 to the price of the machine. A large hard-disk drive is also important for home users. Graphics, sound and video files are much larger than the type of data files typically used by businesses, and some multimedia CD-ROMs copy several megabytes of information to your hard disk.

For your eyes’ sake, be sure to get a good monitor. Never buy a color monitor that has a dot pitch greater than 0.28 millimeters. (The dot pitch is the distance between pixels--the higher the number, the blurrier the image.) There is also the issue of interlaced and non-interlaced monitors. The latter are less likely to flicker, but they tend to be more expensive. Don’t be seduced by a flashy in-store graphics demo: A poor monitor can be disastrous if you’re working with text, so test the monitor by looking at normal-size text in a word-processing program such as Windows Write.

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A lot of home PCs come with a modem, but be sure to ask about its speed. Don’t settle for a 2,400-bit-per-second modem now that 14,400 bps is available for less than $100. The faster modems make a very big difference when you’re on line, and most 14,400-bps modems can also be used to send and receive faxes. You can now buy 28,800-bps modems for less than $200, but very few on-line services currently support that speed.

Also, make sure there’s room to grow. If the machine doesn’t have a CD-ROM player, be sure there’s an “external drive bay” that will accommodate one. Also be sure to have at least two empty expansion slots in case you want to add a scanner or other peripheral.

Unless you have a PC guru in the family, you ought to buy from a company with a toll-free technical support line and a good warranty. I recently had a chance to test Dell and Compaq’s 24-hour customer support and service and came away impressed.

You don’t have to go to a big company for a well-made machine. Don’t overlook no-name “clone” builders in your community--but make sure they’re reputable and able to stand behind what they sell.

What to Look for in a Home PC

* CPU for standard PC (IBM-compatible): A 50-megahertz or 66-MHz 486 DX2 is fine for most users. Get the 75-MHz or 90-MHz Pentium if you’re willing to pay about $500 for faster performance.

* CPU for Macintosh: A Power PC or 68040 that can be upgraded to Power PC

* Memory: Eight megabytes

* Monitor: A “dot pitch” of 0.28 millimeters or less; non-interlaced is better

* Hard disk: At least 200 megabytes; 400 or more is better. Look for an access time of 12 milliseconds or less.

* Modem: 14,400 bit-per-second with built-in fax capabilities

* Support: Buy from either a reputable local builder or a brand that offers toll-free technical support and a warranty, including overnight delivery of replacement parts.

* Extras: A double-speed CD-ROM drive and sound system