Dell's high marks on the SPEChpc tests have plenty to do with the hardware, but they're also the result of heavy tweaking and preparation by the Dell engineers. It's clear they're serious about HPC performance.

The PowerEdge 1955 solution isn't quite as physically elegant as the others in this test, and it certainly lacks the panache of the HP BladeCenter's LCD panel. Dell also uses larger blades than the dual-socket HP BladeSystem c-Class, but packs quite a bit of horsepower into the 7U chassis, which is the smallest of the tested solutions.

Ten blades fit into a single Dell chassis, resulting in a single rack density of 60 dual-socket systems. With the soon-to-be-released quad-core Intel chips, this equates to 240 cores per rack, with a maximum power draw of 3.6 kW.

Each blade sports two 2.5-inch SAS or SATA hot-swap drives with hardware RAID0/1, expanding up to 32GB of DDR2 RAM and dual or quad-core CPUs. The external I/O layout is similar to the HP solution, with integrated switching across a passive midplane and either an integrated Cisco 3030 or a Dell PowerConnect 5316M gigabit blade switch module. Straight gigabit Ethernet pass-through modules are available, as well.

On the FC (Fibre Channel) side of the aisle, you have both McData and Brocade 4GB FC switch modules available, as well as a pass-through module. The PowerEdge 1955 handles InfiniBand with a Topspin pass-through module providing a single port per blade.