First off, if you haven’t been by the Green500 website in a while, swing by. They’ve gotten a full facelift, and they look great. Now let’s take a quick look at the latest lists.

On the TOP Green500 list, which ranks the Top500 entries in order of power efficiency (MFLOPS/W) not Linpack performance, we see IBM leading the list again this year with its PowerXCell 8i offering (I think this is the QS22 blade — comments anyone?). That system takes you through the top 5 slots. Slots 6 and 7 are occupied by custom systems (GRAPE-DR and the Xeon/ATI cluster), and then a run of 15 systems at various positions all owned by IBM’s BlueGene/P. The run is interrupted by a system from Sun and NEC, and then there is a boatload of iDataPlex’s.

The Little Green500 broadens the definition of a supercomputer to help guide purchasing decisions for smaller institutions. According to the website, to be eligible for this list you’ve got to have a system as fast as the 500th ranked supercomputer on the TOP500 list 18-months prior to the release of the Little Green500.

Who leads this list? IBM baby, with QS22’s and BlueGene/P’s, and iDataPlex’s again. IBM doesn’t just lead in energy efficiency — they own it.