Who needs 8Gbps Fibre Channel?

Every time the storage industry reaches a new milestone in interface performance, I question whether engineering excellence has outstripped end users’ actual requirements. Such is the case with the latest generation of Fibre Channel, which doubles performance to 8Gbps.

Outside of the high-performance computing (HPC) space and isolated instances of large databases with very high I/O requirements, I’ve rarely heard of anyone complaining about the performance of 4Gbps Fibre Channel, whether it’s at the disk array, host bus adapter (HBA), switch, or network level. But inevitably, users do migrate to the next speed level, and in the case of 8Gbps Fibre Channel there are a number of good reasons for it.

For one, the Fibre Channel community seems to be following the precedent set with the introduction of 4Gbps FC–namely, pricing for the newest generation will be equal to, or at least close enough, to pricing for the previous-generation products. That worked in the case of 4Gbps Fibre Channel, and it will work with 8Gbps Fibre Channel. If there isn’t any price penalty to pay, why not double your performance?

At press time, end-user pricing for most 8Gbps Fibre Channel products such as HBAs had not been determined (because the adapters are still in the OEM qualification phase), but I’m guessing that they will be priced similar to 4Gbps HBAs.

For sample pricing of an 8Gbps FC SAN “kit,” see the news analysis article in this issue covering HP’s introduction of 8Gbps FC bundles of switches, HBAs, and disk arrays, p. 8. For example, HP’s 8Gbps switch (OEM’d from QLogic) is priced at $5,499 with eight ports enabled. And its 8Gbps FC HBAs (also OEM’d from QLogic) are priced at about $1,300.

Those prices won’t scare the iSCSI crowd, but they’re a good deal, given the performance advantages (relative to 4Gbps FC). And interestingly, HP is primarily targeting first-time SAN users with its 8Gbps FC bundle.

HBA market-share leaders QLogic and Emulex (also covered in the news analysis section in this issue, p. 8) have both begun shipping 8Gbps Fibre Channel HBAs to their OEMs, and Atto Technology will follow suit next month. In addition, QLogic and Brocade are shipping 8Gbps Fibre Channel switches. So the race is on.

But aside from appealing price points, there are a couple other factors that will drive end-user adoption of the next generation of Fibre Channel technology–namely, server/storage virtualization and multi-core and blade servers, all of which often require more performance than 4Gbps FC provides. Couple that with technologies such as PCI Express (PCIe) 2.0 and N_Port ID Virtualization (NPIV) and you’ve got more than sufficient reason to upgrade to 8Gbps Fibre Channel (assuming, of course, that you don’t take the iSCSI–either 1Gbps or 10Gbps–route).

Lastly, the industry wisely decided to go to 8Gbps–rather than, say, 10Gbps–Fibre Channel to preserve backward compatibility.

In next month’s issue, our Lab Review will focus on the performance of HP’s 8Gbps Fibre Channel SAN kit, and preliminary results are very impressive.


Dave Simpson

This article was originally published on March 01, 2008