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AMD's new Phenom processors and Spider platform for desktop systems incorporate some impressive steps forward for the chip maker. The chips, which are made using a 65-nanometer manufacturing process, feature both a native quad-core design and enhanced power-management technology. But when we ran a Phenom- and Spider-based computer through our lab, the results revealed that AMD still has a lot of work to do.

Problems Already?

AMD sent unlocked versions of its 2.6-GHz Phenom 9900 chip to reviewers, but that model likely won't be available on the market until well into the first quarter of 2008, at an expected cost below $350. Until then, the fastest Phenom chips that you'll be able to find are the 2.2-GHz Phenom 9500 ($251 to OEMs) and the 2.3-GHz Phenom 9600 ($283).

A sub-$300 2.4-GHz 9700 chip is scheduled to ship in the first quarter as well, and an unlocked, overclockable Black Edition 2.3-GHz Phenom should be available by the time you read this.

Though both the 9500 and the 9600 appear to be widely available now, AMD recently owned up to a bug in the first generation of its Phenom and Barcelona chips that can cause systems to lock up when running certain rare software workloads at clock speeds greater than 2.4 GHz. A BIOS upgrade is available as a workaround, but according to enthusiast Web site The Tech Report, the workaround slows performance by up to 10 percent. The faster Phenom processors that the company is preparing for release in the first quarter of 2008 should have this error corrected.

Discouraging Results

Now that we have a Phenom CPU in our labs, we can make better comparisons with test systems built around Intel-based processors (see the chart "Penryn vs. Phenom: Two Different Worlds" at the bottom of this page). Our Phenom test setup used the same supporting components --an nVidia GeForce 8800GTS-based graphics board with 320MB of RAM, two Western Digital WD2500AAJS hard drives in a striped RAID array, and 2GB of DDR2-800 RAM--as our earlier Penryn tests did. We tested our unlocked Phenom at both 2.6 GHz and 2.3 GHz on an Asus M3A32-MVP Deluxe motherboard with an AMD 790FX chip set.

When running the Phenom 9900 at 2.6 GHz, our test system posted a score of 107 on WorldBench 6 Beta 2, not all that faster than the average mark of 96 turned in by the systems we've seen based on the last-generation Intel Core 2 Duo E6600 CPU. The E6600, an older chip, goes for $230 from stores such as Newegg.com, compared with the projected $350 price for the 9900.

Of course, the fastest Phenom chip out now is a 2.3-GHz model, and at that speed our test PC's score dropped to 99--not much of an advantage at all for a CPU that costs about $50 more than its aging competition. And there's no comparison to the ultra-high-end Penryn chip we evaluated on the same test bed: That $1000 CPU clocked in at a WorldBench 6 Beta 2 score of 127. By the time AMD's faster Phenom processors are ready to ship, Intel will likely have mainstream Penryn chips ready to compete.

The first Phenom-based PC we could test--a $999 CyberPower Gamer Ultra CF 3870, featuring a 2.3-GHz Phenom 9600 and an ATI Radeon HD 3870 graphics card--didn't fare much better with its score of 95.

AMD currently has no answer to Intel's SSE4 instructions for accelerating specific multimedia operations, which may widen the performance gap further in selected applications. On the other hand, unlike Intel's quad-core models, which are basically two dual-core CPUs using a shared bus interface, Phenom has four distinct cores, which should offer benefits. The performance comparison may evolve as more applications begin taking advantage of multimedia instructions such as SSE and leveraging more than two CPU cores, but given the size of Intel's head start, it's unlikely that AMD will be able to truly close the gap.

At AMD's Phenom launch event in November, we also tested a 2.6-GHz Phenom 9900-based system featuring two of ATI's recently released Radeon HD 3850 graphics cards, an MSI motherboard using AMD's 790FX chip set, and 2GB of DDR2-1066 RAM. On WorldBench 6 Beta 2, AMD's test system received a score of 105, significantly faster than the 93 posted by a Polywell 580CF-2900 with AMD's last-generation 3-GHz Athlon 64 X2 6000+, though not nearly the 32 percent gain that AMD touts. While representing an impressive boost over AMD's previous CPUs, it's nowhere near enough to make Intel sweat.

Penryn vs. Phenom: Two Different Worlds

Click the thumbnail below to view the full-size image of our chart.