Supercomputer for the masses

Until now, most high-performance computing clusters were hand-built affairs found mainly in large universities, lovingly designed by enthusiastic professors and tended by sleep-deprived graduate students. But now Dell — which was appropriately enough started in a dorm room — has begun to commercialize the HPC (high-performance computing) market, offering pre-configured supercomputer clusters that combine everything from the servers to racks to software integration.

Thus, now you can buy an eight-node 16-processor HPC cluster off the shelf from Dell, for only $130,000 plus shipping and applicable sales tax but you’ll have to phone in the order, because Dell doesn’t yet offer HPC clusters from its Web site. Cables are included, but on-site “rack and stack” service costs extra.

As I found during a hands-on review of an eight-node, 16-processor cluster at Dell’s Palmer campus in Austin, Texas, the individual servers (Dell’s new Itanium 2-based PowerEdge 3250), are nothing exceptional; they’re little more than dual Intel processors and an Intel motherboard slapped into a Dell case. However, the company’s integration and total clustering solution is excellent.

The core of a Dell supercomputer cluster is an array of identical server nodes, which do the heavy lifting. Dell offers both the Itanium 2-based PowerEdge 3250 server, as well as a dual Xeon-based PowerEdge 1750 server. Most real-world clusters would have far more nodes than I tested at Dell’s lab, by the way; a starting point of 32 or 64 nodes (that is, 64 to 128 processors) would be more realistic for a genuine supercomputer. Dell also provides separate servers for functions such as job scheduling and task distribution, as well as providing access to shared data.

Nearly as important as the servers are the network interconnects that bind the array together. Most Dell high-performance clusters contain two parallel networks: Gigabit Ethernet, for linking the individual nodes with the management servers and shared storage, and a proprietary low-latency, low-overhead network such as Myrinet for interprocess communication between the nodes.

On the software side, the server foundation is Red Hat’s Advanced Server 2.1 version of Linux. (Dell also offers Windows-based HPC clusters but only on an as-requested basis, according to the company.) On top of Linux run two products from MPI Software Technology: the MPI/Pro cluster software, which provides the protocol stack for MPI (Message Passing Interface), the messaging middleware between the nodes; and Felix, a management tool that pushes software images from a management server out to the computing nodes. Felix also runs remote Linux commands in parallel across the cluster. Also vital is Ganglia, an open source, HPC, distributed monitoring application, plus a gaggle of other tools and utilities.

A Single Node

Before working on the cluster, I examined one of the PowerEdge 3250 servers. Dell has carefully marketed this device, its second 64-bit server, as being designed for scientific computing and HPC clusters; in fact, the company refused to send InfoWorld a single stand-alone server for review, insisting that it could only be properly evaluated within an HPC environment. (The previous model, the PowerEdge 7150, used the original Itanium chip and was introduced in May 2001.)