Soupin' up the bus

Simulations of galaxy formations. Complex drug designs. Studying the path of dust clouds. This is just a sampling of the compute-heavy tasks that Phil Williams has to support on his research network at the University of Nottingham, in England.

"The calculations we do are a combination of lots of repetitive serial jobs and highly parallel jobs," Williams says. "Each of these [calculations] takes only a few seconds to occur, but it takes us many, many hundreds of thousands of CPU hours to simulate in a computer."

Despite Gigabit Ethernet connections, Williams' servers - a cluster of 512 dual-processor Network File System-mounted file servers - were getting severely bogged down. "The CPUs were spending all their time handling the connection so that the performance on the job disappeared to nothing," he says. "The interconnect was definitely becoming the limiting factor - it was holding back the amount of data we could calculate."

A trio of high-speed interconnect technologies is aimed at alleviating exactly that kind of strain: veteran technology InfiniBand; newcomer EtherFabric , an Ethernet-based offering from start-up Level 5 Networks; and iWarp, an Ethernet-based technology being put through its paces at the University of New Hampshire (UNH) Interoperability Labs in Durham. All three technologies offload the network connections from the server CPU so that servers can catch up to the network's Gigabit bandwidth speeds. And the buzz on them is picking up as users look for alternatives to 10G Ethernet to handle their growing network loads.

"A push toward sophisticated applications will mean an increase in video over IP, the need for an enriched buying experience over the Web, and the need for improved rendering of images," says Ann MacFarland, a director at The Clipper Group. For IT managers who don't want to make the leap to 10G Ethernet, the combination of big pipes, real-time traffic, heavy computing and burdensome graphics will choke their networks if they don't reconsider their interconnects, she says.

The infrastructure you have

EtherFabric, a combination of a network interface card (NIC) and software that uses a corporation's current Ethernet switch infrastructure, fit the bill for Williams at the University of Nottingham. EtherFabric gains performance improvement for servers by distributing a TCP/IP software stack to each application on the server. Each application then can directly access memory on the NIC, which alleviates the copying of data to system memory and the over-utilization of CPUs.

"The NIC handles the network so the CPU isn't being hammered by the kernel and being interrupted to handle network traffic," says Williams, who wanted to preserve his investment in Gigabit Ethernet pipes, while achieving high performance and low latency.