FlashMob Networks PCs for Ad-Hoc Supercomputer

By linking desktop PCs and notebooks together through an Ethnernet network, University of San Francisco researchers aim to make supercomputer oomph "available for use by ordinary folk," a co-creator says.

University of San Francisco researchers are attempting to create a poor mans supercomputer cluster by linking desktop PCs and notebooks together through a conventional Ethernet network.

Part social movement, part scientific effort, the "FlashMob" software is named after the short-lived social phenomenon of random people coming together for brief activities. John Witchel, a USF graduate student and FlashMob co-creator, said he plans to make the software open-source. In about a week, USF will host about 1,000 people in its gym to demonstrate the technology, with a goal of cracking the Top 500 list of supercomputers.

The software is designed to put supercomputing back into the hands of the people. Massive clusters such as ASCI White and the Earth Simulator in Japan cluster hundreds of nodes together, at a cost of tens of millions of dollars.

"What this really means is that supercomputers are not available for use by ordinary folk," Witchel said. "If you and I want to study the hole in the ozone layer, the answer is, we cant."

The FlashMob software requires no operating system. Instead, the software is burned to a CD-ROM disk, which then controls the PC when it is rebooted. A user then plugs into the local network, and the software begins scanning for other FlashMob clients. For security reasons, the hard drive is not accessed at all, Witchel said, preventing personal information from being leaked to the network and also preventing the spread of viruses and other worms. When a user completes a task or must leave, all he or she needs to do is disconnect the PC, remove the CD-ROM and reboot.

FlashMob fits somewhere in between a clustered supercomputer, which uses modular computing nodes or blades coupled with extremely fast interconnects, and distributed computing , where a server assembles chunks of data processed by PCs that are linked through the Internet, such as the SETI@Home project.

FlashMob is perhaps most similar to the 1,100-node cluster of Apple Macintosh G5s, later replaced by Apple Xserve servers, that Virginia Polytechnic Institute and State University began assembling in August 2003.

Whats the difference between FlashMob and the Virginia Tech cluster? "About $5.2 million," Witchel replied. "Virginia Techs effort was very impressive, and FlashMob would not exist without Virginia Tech leading the way," he said. "But youll recall they built a specific building for it, complete with a cooling system."

Next Page: Designing a Grass-Roots Supercomputer