If you've got the slots, HBA and RAID card vendors finally have a few cards that support the latest bus architecture for Intel-based servers he last obstacles standing in the way of PCI Express are slowly falling away, and the stage is set for the next-generation serial bus architecture to step up as the successor to PCI-X, with which it is software-compatible, while providing much better performance.
Sales of servers with PCI Express are expected to take off this year. Today, only about 5% to 10% of servers ship with any PCI Express components, says Sean Hall, channel marketing manager at Broadcom Corp., a semiconductor company in Irvine, CA. But when you consider newer server designs, approximately half of them ship with at least a few PCI Express slots, he says, and that number should increase as the year rolls on.
PCI Express storage adapters such as RAID cards and Fibre Channel (FC) host bus adapters (HBAs) are also starting to trickle in. LSI Logic, for example, has a PCI Express version of its Ultra320 SCSI MegaRAID card, while Emulex has shipped and qualified its LP10000Ex family of FC HBAs. Emulex also announced recently that the cards had been qualified by partners Dell and EMC. Mike Smith, executive VP of worldwide marketing at Emulex, says that other server and storage array vendors are also qualifying the card.
Whether you should consider PCI Express RAID cards or HBAs depends on your performance requirements. "The only time PCI Express comes in [rather than PCI-X] is if you have a dual-port, four gig HBA or 10 gig Ethernet," says Charlie Kraus, director of LSI Logic's HBA business unit, as they would saturate the PCI-X bus. Furthermore, most early PCI Express storage adapters are still based on bridges, not native PCI Express cores. "There's only one reason to like bridges, and four reasons to hate them," Kraus says. The lone pro? "Time to market." The cons? Price, power consumption, real estate and buggy firmware. In other words, it may be better to wait until second-generation models appear.