Penryn, Phenom PCs: Fast, Not Phenomenal

Dell's multimedia-theme XPS 420 midsize tower (left), and War Machine's impressively powerful M1 Elite system.
Dell's multimedia-theme XPS 420 midsize tower (left), and War Machine's impressively powerful M1 Elite system.
Mainstream and boutique PC vendors are having a field day releasing new systems with next-generation Intel Penryn and AMD Phenom processors. We found Intel Penryn-based desktops to be substantially faster than the one similarly priced AMD Phenom system we tested, but in general not much faster than systems configured with Intel's previous-generation processors.

Penryn and Phenom are designed differently. Whereas Phenom chips use four distinct cores, quad-core Penryns consist of two dual-core processors sharing the same piece of silicon and a bus interface. The Phenom approach may eventually lead to better multitasking performance. On the other hand, Penryn CPUs are manufactured using a 45-nanometer process that fits more transistors into less space, allowing manufacturers to produce more chips from the same amount of material while consuming less power than is required for the 65-nm last-generation dual/quad-core Intel CPUs and the AMD Phenoms. Aside from the die-shrink, the biggest change Penryn introduces is Intel's new SSE4 instruction set, which can speed up applications written to work with it. For example, Adobe is updating the next version of its Premiere Pro video editing application with SSE4 support.

On the system level, AMD takes the concept of linked graphics cards (an idea that it calls 'CrossFire' and that nVidia refers to as 'SLi') up a notch, offering the ability to use four cards in a single PC. We plan to test such systems as they become available.

We looked at three new PCs configured with Intel's top-of-the-line Penryn chip, the 3-GHz QX9650 Core 2 Extreme: Dell's XPS 420, Puget Systems' Puget Gaming Computer, and War Machine's M1 Elite. We also took a sneak peek at a not-yet-available Dell XPS 420 system carrying Intel's mainstream Penryn processor, the Q9550. Dell says it plans to release PCs with this CPU in the first quarter of 2008.

On the AMD side, the system we looked at (Polywell's $2999 Poly 790FX) carried AMD's 2.2-GHz 9500 Phenom CPU and its equally new 790FX chip set.

Four of the five systems in our test group captured spots on our Top 5 Penryn & Phenom Power Desktops chart, though first place on the chart went to a PC we examined a couple of months earlier, CyberPower's Power Infinity Pro.

Find the Very Latest Charts of Penryn & Phenom Desktops and of Power Desktop PCs

PC World's Top Intel Penryn or AMD Phenom Desktop PCs (chart)
We can update online charts more rapidly than the charts appearing in the print magazine, so sometimes the two versions will differ. To see the chart that appeared with the print-magazine version of this story, click the graphic. Click on the links below for the latest Intel Penryn or AMD Phenom Desktop PC rankings or a comprehensive list of all Power Desktop PCs we've tested.

Products reviewed in this article:

Dell's XPS 420 Shines

Loaded with 3GB of memory, the Q9550-equipped Dell XPS 420 earned a score of 122 in our WorldBench 6 Beta 2 benchmark. That's just shy of the 126 posted by its pricier QX9650-based (but otherwise identically configured) XPS 420 sibling. Meanwhile, the QX9650-equipped War Machine M1 Elite scorched its way to a WordBench 6 Beta 2 result of 131. It performed strongly in every facet of the test suite, and put up excellent gaming numbers as well.

Puget Systems' Gaming Computer, which was configured almost identically to the War Machine, scored 124. On many components of our WorldBench 6 Beta 2 test suite, the Puget ran neck and neck with the War Machine, but it fell behind in large-file-intensive tests such as creating disc images in Nero 7 Ultra edition, most likely because it was one of the few systems competing for a spot on our chart of top Penryn and Phenom PCs that didn't employ two hard disks in a striped array.

In our tests, despite the War Machine's blazing performance, Penryn 3-GHz QX9650 Core 2 Extreme-based machines in general didn't significantly outperform PCs based on Intel's older 65-nm processors. This is evident from the WorldBench 6 Beta 2 scores posted by the CyberPower Infinity Pro (124) and the E6850-based Xi MTower PCIe-two systems equipped with Intel's previous high-end CPU, the 3-GHz Core 2 Extreme QX6850; both achieved high rankings on our online Power Desktop PCs chart But since none of the applications in the WorldBench 6 Beta 2 test suite are optimized for the four cores offered by the Intel Q and QX chips or their Phenom competition, we're essentially comparing just the first two cores on all these processors.

Polywell's Phenom PC

Polywell's Poly 790FX boasts AMD's new 2.2-GHz Phenom 9500 CPU, its 790FX chip set, and ATI's 512MB HD 3850 graphics board.
Polywell's Poly 790FX boasts AMD's new 2.2-GHz Phenom 9500 CPU, its 790FX chip set, and ATI's 512MB HD 3850 graphics board.
The 2.2-GHz Polywell Poly 790FX costs $270 more than the 2.83-GHz Q9550 Dell XPS 420 that outscored it on WorldBench 6 Beta 2, 122 to 95. The Poly 790FX had only one graphics board (a 512MB ATI HD 3850), installed in one of four PCIe x16 slots; but it had a 1000-watt power supply, simplifying the task of upgrading to four graphic boards if you wanted to in the future.

Well-Built Specimens

Not surprisingly, each of these high-end systems had a handsome case design. Like the first War Machine M1 Elite we tested, the new QX9650-equipped M1 Elite we looked at comes packaged in an impressive, all-black case with lots of free bays and blue bling lighting. Puget Systems' Puget Gaming Computer is a pricey newcomer ($5765 list), but it turned in very good performance and has one of the best-laid-out interior designs we've ever seen, starting with an Antec P182 case. Assembled with virtually no obstructing cables and tons of easily accessible drive bays, it's a thing of beauty.

Meanwhile, the two Dell XPS 420 models we tested have great-looking glossy black finishes. Each model came configured with a Blu-ray drive (read-only), front-mounted S-video and RCA ports (which include a hardware video transcoding option dubbed the 'Xcelerator'), a top-mounted 2-inch LCD that employs Microsoft's Sideshow secondary display technology, and integrated Bluetooth to handle the bundled wireless keyboard and mouse. The 'X' in the 3-GHz QX9650's CPU name stands for Xtreme, and normally it indicates that you can overclock PCs with the chip. However, though Dell supports Extreme processors for the XPS 420, it does not provide utilities or BIOS support for overclocking. The QX9650 XPS 420 also costs $1000 more than its sibling equipped with the 2.83-GHz Q9550 chip.

Phenom Problems?

If you're thinking about buying a Phenom-based system, you should be aware of a bug known as the TLB erratum. This flaw can cause a Phenom computer to lock up on extremely rare occasions-namely, when all four cores are working full bore. Right now, the only software known to trigger the freeze is VMware. In our testing, we didn't encounter a Phenom freeze; and most motherboard BIOSs have been patched to avoid it. AMD admits, however, that the BIOS workaround imposes a substantial performance hit on the PC, so we recommend that you not apply the patch unless your machine actually locks up. Since the BIOS for Polywell's Poly 790FX's Gigabyte GA-MA790FX-DQ6 motherboard hadn't implemented the patch, the scores it earned represent the chip's full performance potential at this time. AMD has promised to release a version of its software overclocking utility that will permit you to toggle the BIOS workaround on and off. That way you'll be able to choose between top performance and guaranteed stability.


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