The latest Top 500 Supercomputer list is out. At the very tip-top, you'll find Tianhe-2. This supercomputer, developed by China’s National University of Defense Technology, is once more the world’s fastest supercomputer with a performance of 33.86 petaflop/s (quadrillions of calculations per second) on the Linpack benchmark. Also on top, as it has been for more than a decade now, you'll find Linux.
In the November 2013 listing, 482 of the world's top supercomputers run Linux. The free, open-source operating system is followed by Unix, with eleven; four systems running a mix of operating systems, two with Windows and a single system running BSD Unix. That's an advantage of 96.4 percent for Linux to 3.6 percent for everyone else, if you're keeping score at home.
The vast majority of these Linux hot-rod computers use cluster architectures with 86.4 percent. Only 15.4 percent use a massively parallel processor (MPP) design.
A related development, behind the high-tide of Linux, is that most of these supercomputers use AMD and Intel chips. To be exact, 82 percent use Intel Xeon chips with the Xeon E5 SandyBridge processor leading the way. 9 percent use AMD Opteron and 8 percent use IBM Power processors. All of these chips can, and do, run Linux on supercomputers.
Just over 10 percent of supercomputers, 53 systems, use accelerator/co-processor technology. Of these, 38 use NVIDIA chips, 13 systems with Intel's Xeon Phi and two use ATI Radeon.