The transceiver, which can be used as the optical component of a network interface card (NIC) or as a network device such as a switch, is based on the XPak specification, which allows for a smaller transceiver than had been used previously in 10GbE interfaces.
Unlike transceivers designed using the XenPak specification introduced earlier, XPak transceivers can be integrated into NICs that plug into the slots in typical computing hardware. The XPak transceiver is about half the cost of a XenPak part and consumes a third as much power, according to Intel.
In addition to 10GbE, a version will be available for the 10Gbps version of Fibre Channel, the networking technology most commonly used in storage networks.
Uses of 10GbE have been limited to equipment for service-provider networks and enterprise backbones, where the size and cost of XenPak have not been a major problem.
Intel's LAN Access Division, which demonstrated a XenPak-based NIC in May, believed it would help 10GbE penetrate the enterprise data centre. The primary benefit of XPak for servers will be NICs with a smaller form factor and lower power consumption.
The bandwidth limitations of existing data buses, such as PCI and PCI-X, mean companies have been unable to take advantage of network connections faster than Gigabit Ethernet or 1Gbps Fibre Channel. Emerging faster bus technologies such as PCI-X 2.0 and Infiniband will remove the bottleneck between the NIC and the server or storage device.
A PCI-X 2.0 dual data rate bus, which would probably become available in the second half of 2003, would transfer about 2Gbytes per second, or about 16Gbps.
XPak was established through an open agreement betwen Intel, Infineon Technologies and Picolight, which was published in May. It is intended specifically for enterprise networks. The specification works only with multimode fibre, the short-range type used in most enterprises.
XenPak can work with multimode as well as with single-mode fibre, which can handle distances of up to 40km, but it is more expensive to buy and install. Single-mode is unnecessary in most enterprise applications.
For network equipment makers, XPak paves the way for switches and other devices that pack more ports into a given size box.
SANs (storage area networks), which link several storage devices in their own high-speed network via a specialised switch, today are dominated by Fibre Channel. Ethernet is less expensive to buy and set up, but lacks the on-time delivery guarantees available with Fibre Channel. The big increase in Ethernet speed from 1G bps to 10G bps may change the equation
However, change comes slowly in the storage business. For example, although Fibre Channel is now available in 2Gbps and 10Gbps, most deployments still use the 1Gbps version.
The Intel TXN17201/9 XPak Optical Transceiver is available in sample quantities now and will be generally available to original equipment manufacturers in January, for a volume price of $500 (£327) each.