Emulex Corp.'s LightPulse 9002 host bus adapter boldly pushes Fibre Channel SANs to 2G-bps transfer rates, effectively doubling the performance of current Fibre Channel offerings. However, it will be lonely at the top of the Fibre Channel storage world until next year, when the rest of the storage industry catches up.
In eWeek Labs' tests using Intel Corp.'s Iometer benchmark, which measured the LP 9002's ability to process read/write requests, the adapter offered impressive raw performance numbers. But even with blazing capabilities, the LP 9002, which will be released this month, won't provide much value until other Fibre Channel components can network at these speeds.
Running at half-duplex speed, the LP 9002 was able to crank out a maximum of 194MB per second on sequential read tests, or almost double the 100MB-per-second theoretical maximum of other Fibre Channel switches. It's worth noting that these are the drag-racing numbers of storage benchmarksâ€"they might look impressive but mean little for most practical uses.
We didn't see much falloff when we ran the test suites using randomized write and read requests: The LP 9002 clocked an impressive 175MB-per-second maximum throughput.
Emulex officials said they expect these numbers to double when Fibre Channel switches with full-duplex capabilities come to market, but it will be at least six months before we can verify this claim.
The test system we used was a relatively low-end Compaq Computer Corp. desktop machine with a single 800MHz Pentium III Xeon processor and 256MB of RAM.
Throughout testing, we were impressed that the CPU on the desktop was not overly taxed (we saw roughly 5 percent CPU utilization in randomized read/write tests).
On the storage side, we used a standard JBOD (just a bunch of disks) configuration with Seagate Technol ogy LLC Cheetah 4X15 hard drives spinning at 15,000 rpm.
At US$2,195, the LP 9002 costs roughly 30 percent more than 1G-bps Fibre Channel host bus adapters. However, because the LP 9002 can run at both speeds, we believe it's a good investment for sites that can afford the difference.
Future concerns
The LP 9002's autonegotiation capability (it can automatically determine whether a device processes at 1Gbps or 2Gbps) brings up an interesting issue that Fibre Channel vendors must address.
Currently, there is no standard in place for autonegotiation, although most vendors expect one to be ratified later this year before products ship.
Emulex has developed autonegotiation for its cards, and this capability is enabled from the LP 9002's firmware. When a standard is finalized, a firmware upgrade will be all that's needed to comply, Emulex officials said.
In tests, the JBOD storage unit could not talk to Emulex's older 1G-bps cards, which suggests that there are issues to iron out before 2G-bps Fibre Channel storage can be widely deployed or introduced in heterogeneous networks.
The JBOD could be rigged to work with the older cards, but we had to change jumper settings on the hard drives to run at 1G bps.
