Savings in the cards
Just as the fewer servers you run means lower power consumption, so too does the number of switches they connect through. Jerome Wendt, president and lead analyst with Data Centre Infrastructure Group, an independent consultancy based in Omaha, Neb., points to a couple of new technologies that can reduce the number of cards and switches in the data centre.
Infiniband isn’t actually brand new; it emerged from the Future I/O versus Next Generation I/O battle of the late 1990s. For a high-end data centre, there are advantages, says Wendt; rather than installing six or seven Ethernet or Fibre Channel cards in a server, the job can be done with a pair of Infiniband cards.
On the downside, an Infiniband director is required to segment out Ethernet and Fibre Channel traffic. And, says Wendt, “companies have to get up to speed on Infiniband.”
But the cost of Infiniband is coming down to the point that it’s comparable to Fibre Channel. “It’s not prohibitively expensive,” says Wendt – about $600 gets you 20 Gbps of throughput, down from $800 to $1,000 a year ago, and about a quarter of the cost of the required Fibre Channel cards. Driving prices down is the demand from the Linux-based high-performance computing market, connecting clusters and supercomputers, says Wendt.
Wendt says new network interface cards (NIC) from Intel and Next-Gen can create V-NICs or virtual NICs. These allow every virtual server on a physical host to have its own MAC and IP address instead of sharing with the other servers in the box. They’re more expensive than the previous generation of NICs, and Wendt doesn’t see the market taking off tomorrow. They’ll likely see more play as more companies adopt 10Gbps Ethernet. “It’ll be another six to 12 months before we see any adoption,” Wendt says.
And Next I/O has developed a PCI Express card that extends the backplane of the physical server to an appliance with segmented Ethernet and Fibre Channel connections. “You can connect all your different protocols” without buying cards for each, Wendt says. “It’s an interesting way to play server farms.”
In general, Wendt says, higher throughput means fewer switches and directors to draw power. It may not be an immense saving, but the incremental adds up.