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Emerging technologies update

PCI Express and 802.11g appear to be speeding toward success in the enterprise, while power over Ethernet is making steady progress in selected situations. But it's been slow going for Bluetooth.

December 20, 2004 12:00 PM ET

Computerworld - PCI Express was designed to eliminate I/O bottlenecks for everything from video graphics to 10Gbit/sec. Ethernet adapters. 802.11g offered a backward-compatible way for enterprises to upgrade their 802.11b wireless LANs to higher speeds. Power over Ethernet would eliminate the need to use AC power for WLAN access points, IP phones and other equipment. Bluetooth promised to end cabling clutter on the desktop.

Computerworld has covered the introduction of each of these emerging technologies over the past two years. In that time, some have gained ground; others have fallen short. Here's a report card on where each stands.

PCI Express: Adding Fast Lanes

After more than a year of slow, steady progress, PCI Express, a new I/O technology designed to replace the Peripheral Component Interconnect expansion bus used in PCs and servers, is ready to roll. Intel Corp. released the first PCI Express motherboard and chip sets this past summer, systems began shipping in August, and a few adapters are now available.

Developed through the PCI Special Interest Group, PCI Express (also called PCIe) replaces the PCI bus with a serial architecture that uses up to 16 sets of wires, or "lanes," to support bandwidth ranging from 500MB/sec. to 16GB/sec. For the most part, PCI Express is designed to solve I/O bottlenecks that most users have yet to experience, but IBM, Hewlett-Packard Co. and Dell Inc. have all rolled out servers that include both traditional PCI and two or more "4x" (four-lane) PCI Express slots to stay ahead of user demand.

On commodity servers, PCI Express appears to have won a battle with PCI-X 2.0, a competing 2GB/sec. standard once supported by HP. "Ethernet and storage-controller vendors started flipping from PCI-X 2.0 over to PCI Express, so we're moving with the market," says Colin Lacey, director of market strategy for the ProLiant server line at HP.

But PCI-X 2.0 will arrive on high-end servers next year, both because PCI Express isn't fully mature and PCI-X 2.0 is likely to be available sooner than comparable 8x implementations of PCI Express, says Tom Bradicich, chief technology officer for IBM's xSeries and BladeCenter servers. Eventually, even these systems will migrate to PCI Express, he says.

PCI Express is already replacing the accelerated graphics port for high-end graphics on PCs. For most other I/O needs, however, PCI Express is overkill. On servers, early PCI Express adapters focus on technologies likely to max out current 1GB/sec. PCI-X bus, including 10 Gigabit Ethernet, RAID controllers and Fibre Channel. But server buyers should be cautious, says Nathan Brookwood, an analyst at Insight 64 in Saratoga, Calif. "As long as they are not finding PCI-X to be a bottleneck, it's still a preferred solution because it's tried and proven," he says.

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