Chips With Two Brains

Dual-core processors divvy up your PC's workload


Has your computer started driving you crazy? You'll be typing along on an e-mail when suddenly the PC stops responding to your keystrokes, then catches up a few seconds later. Or a program that used to load in a few seconds inexplicably takes three times as long. Processors are faster than ever, but the demands of even routine computing are overwhelming them.

Even if you haven't changed the way you use your PC, it's likely working a lot harder than it did a couple of years ago, especially if you've added a broadband Internet connection. Firewall, antivirus, anti-spyware, and anti-spam programs are -- or should be -- churning away in the background, inspecting everything that moves in and out of your PC. Many of us also run desktop search software, which strains the system each time it updates its index. And multimedia content in Web pages and e-mail demands extra processing power.

Help is at hand, and it's not just another boost in processing speed. Fast PCs are bogging down because no matter how fast a processor runs, it can only do one thing at a time. Today's computers offer the illusion of doing many things at once, but performance drops as they try to switch rapidly among tasks.

The best route to improvement is to let the operating system divide the work over more than one processor. That has become practical with the advent of PC chips that put two processor "cores" on a single piece of silicon. The concept is not novel, since computer companies have long sold high-performance workstations with two separate processors. But the dual-core approach is much cheaper because the cores can share expensive high-speed memory and use a single set of support chips. Intel (INTC ) calls its version the Pentium D. Advanced Micro Devices' (AMD ) entry is the Athlon 64 X2.

I HAVE STOPPED EXPECTING NEW CHIPS to deliver dramatic changes, so the performance of the dual-core processors was a welcome surprise. I tried a Dell (DELL ) Dimension 5100C, an attractive small desktop powered by a Pentium D (from $1,049), and a high-end Hewlett-Packard (HPQ ) Pavilion D4100E minitower, which is powered by an AMD X2 (from $1,439).

I mostly used them for my everyday tasks: writing, e-mail, Web browsing, playing music and video, burning a CD or two -- not very taxing duty, especially for the HP, but probably typical of how most people use their computers. The main difference I noticed was the absence of annoying pauses that have become commonplace on my regular office desktop, a Dell Precision workstation with a 2.4-Ghz Pentium 4. For example, the older Dell slows to a painful crawl when the X1 desktop search software is refreshing its index so it can instantly locate search terms in files and e-mail messages. The X1 stops indexing when another application becomes active. But Windows isn't very efficient at such switching, so I end up waiting while X1 gets out of the way. No such problem with the dual-cores: Even when I forced X1 to recreate an index from scratch, making it use maximum resources, the new chip kept other programs humming, and the indexing went quickly.

Do you need a dual processor machine today? Current prices may give you pause. A Pentium D fetches a premium of $100 to $200 over a Pentium 4, and the AMD chip, targeted at the high end of the market, adds more than $600. But AMD will soon announce cheaper models and Intel too plans to push prices down quickly. (Laptops won't go dual-core until early 2006.)

By the end of next year, the case for trading up will be more compelling. Microsoft (MSFT ) has not revealed the hardware requirements for the new version of Windows due in late 2006, but by all reports, taking full advantage of the new features will demand a big leap in processing power. Fortunately, by then dual-core chips will probably be at least as cheap as the single processor models they are replacing.

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By Stephen H. Wildstrom

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