The Power and Legacy of Virginia Tech’s Mac-Based Supercomputers

Virginia Tech built System X, a supercomputer assembled from 1,100 dual 2.0 GHz Power Mac G5s running Mac OS X, for $5.2 million in summer 2003, targeting 10 teraflops. When it went live that fall, it ranked as the world's third-fastest supercomputer and the fastest at any academic institution, a striking result given that the top machine, Japan's Earth Simulator, cost roughly $400 million. The project, led by faculty member Srinidhi Varadarajan, demonstrated that off-the-shelf commercial hardware could compete with custom-built systems at a fraction of the price, echoing David Bader's 1998 Linux cluster work with Intel Pentium II parts. Virginia Tech faculty and students could use the machine free of charge, running projects across nodes that shipped with Mac OS X 10.2.7 and were slated to move to Panther. The result matters because it helped legitimize commodity clustering as a path to high-performance computing and cemented Apple's brief credibility in the category. What to watch next: whether Apple's shift away from the PowerPC architecture toward Intel, announced in 2005, would leave System X's G5-based design stranded.