The October 25th edition of the interim Top 500 Supercomputer list includes a new entry, IBM's Blade Center JS20 G5-based cluster. This machine hits 14550 Gflops/s, utilizing 2520 CPUs at 2.195 GHz. That represents an efficiency of 65.8%, which is higher than Virginia Tech's 60.5% efficiency.
The IBM cluster lands in 5th place on the list, and pushes the VT system down a notch to 7th. That puts two G5 supercomputers in the top ten for the next list, which will be unveiled in a few weeks.
Update October 26, 2004:
IBM is now listed at 20.45 Tflops/s, with 3564 2.2 GHz G5 processors (65.5% efficiency). That puts them in 3rd place, behind Japan's Earth Simulator.