Cisco may not have said it directly, but it appears to
have abandonedInfiniBand
.
The company is getting behind
Data Centre Ethernet in a big way with its
Data Centre 3.0 strategy, which is designed to provide
converged networking for the datacentre. It has taken standard
high-speed Ethernet and added standards-based extensions for
services such as quality of service and lossless transmission.
"The adoption of Data Centre Ethernet will help enable a unified
fabric in the datacentre, reducing costs and simplifying
management," the firm said in a statement.
"Many high-performance compute applications already run over
Ethernet. With the enhancements to Ethernet and migration to
10
Gigabit Ethernet [or 10GbE], Cisco believes that the subset of
applications that require high bandwidth and low latencies can be
supported effectively on Ethernet," the statement said.
That does not seem to leave much room for InfiniBand.
Change of
direction
It is a strange position to take for a company that was piling
millions of dollars into InfiniBand just a few years ago. The firm
spent $250m on
InfiniBand switching firm Topspin Communications in 2005, and
upgraded its line of switches with that company's technology the
following year.
It made it clear even then that it was unifying the two in the
network, so that Ethernet and InfiniBand could be used together in
the same switch and configured with the same management console.
Now, Cisco appears to believe Ethernet has evolved to the point
where other protocols such as InfiniBand are no longer
necessary.
"Cisco is pushing it because it wants to do Fibre Channel over
Ethernet. Ethernet is trying to build in things that InfiniBand
already does," says Kevin Judd, senior staff product manager at
InfiniBand SAN switching vendor QLogic and co-chair of the
InfiniBand Trade Association's marketing working group.
Slow adoption
Darin Stahl, lead analyst at industry watcher Info-Tech Research
Group, agrees that 10GbE still has a lot to prove. "The
approval happened in 2002, and the adoption rate has been much
slower than I would have expected given the promise of what it
could do. The biggest issue around that is the cost per port," he
says.
Brian Sparks, who co-chairs the IBTA working group along with
Judd, says that the port cost for high-speed Ethernet currently
makes it impracticable for many datacentres. The IBTA's figures put
10Gbit/sec InfiniBand at $22 per Gbit/sec, compared with $85 per
Gbit/sec for 10Gb/sec Ethernet. "We do not project 10GbE to become
competitive until at least 2010," he says.
Sparks also alludes to rumours of
Cisco's forthcoming entry into the blade server market. "Cisco
is doing things that make the server manufacturers do a double
take. The likes of Hewlett-Packard, IBM, Dell and Sun are looking
for a way to compete with Cisco solutions, and see InfiniBand as a
way to compete against Cisco, at a better cost," he says.
Perhaps, but server suppliers such as Fujitsu are nevertheless
promoting the use of high-speed Ethernet, even in high-performance
computing environments normally considered a sanctuary for
InfiniBand. A
white paper from the company points to the ratification of the
10GBase-CX4 10GbE over copper standard in 2004 as a critical point
in time for the standard, because it dropped the cost per port.
He adds that InfiniBand's
low latency design makes it particularly well-suited for the
high-performance computing space. 10GbE dropped the half-duplex
mode that required CSMA/CD to handle packet collisions, and moved
to full duplex instead. But the latency of the ratified, unmodified
protocol is still higher than InfiniBand.
"There are 10GbE suppliers applying technologies to lower the
latency. Right now they are getting latency of three microseconds,
but that is still three times the latency that InfiniBand is
offering," says Judd.
Infiniband's
days are numbered
Nevertheless, Hamish Macarthur, founder of market watcher
Macarthur Stroud International, is sceptical about the protocol's
chances.
"The main system suppliers are starting to close back in again
to more direct attached storage. A good example of that is blade
servers, some of which now have 2.5in disk drives," he says,
arguing that suppliers are trying to gain end-to-end control of
server and storage space, which limits the scope for
InfiniBand.
"The issue of what happens to InfiniBand presents a big question
mark. There may be lessons from that for the development of new
architectures, but as a protocol itself it has limited time."
Macarthur says.
If Ethernet does encroach on InfiniBand's market, it will take
some years before it does significant damage. And the inevitable
shelving of capital-intensive infrastructural IT projects for the
next year (at least) will do nothing to help it. Nevertheless, the
constantly evolving standard should not be discounted.
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