LINPACK benchmark. IBM Roadrunner used the PowerXCell 8i version of the Cell processor, manufactured using 65 nm technology and enhanced SPUs that can handle double precision calculations in the 128-bit registers, reaching double precision 102 GFLOPs per chip. Cluster computing Clusters of PlayStation 3 consoles are an attractive alternative to high-end systems based on Cell blades. Innovative Computing Laboratory, a group led by Jack Dongarra, in the Computer Science Department at the University of Tennessee, investigated such an application in depth. Terrasoft Solutions is selling 8-node and 32-node PS3 clusters with Yellow Dog Linux pre-installed, an implementation of Dongarra's research. As first reported by Wired on October 17, 2007, an interesting application of using PlayStation 3 in a cluster configuration was implemented by Astrophysicist Gaurav Khanna, from the Physics department of University of Massachusetts Dartmouth, who replaced time used on supercomputers with a cluster of eight PlayStation 3s. Subsequently, the next generation of this machine, now called the PlayStation 3 Gravity Grid, uses a network of 16 machines, and exploits the Cell processor for the intended application which is binary black hole coalescence using perturbation theory. In particular, the cluster performs astrophysical simulations of large supermassive black holes capturing smaller compact objects and has generated numerical data that has been published multiple times in the relevant scientific research literature. The Cell processor version used by the PlayStation 3 has a main CPU and 6 SPEs available to the user, giving the Gravity Grid machine a net of 16 general-purpose processors and 96 vector processors. The machine has a one-time cost of $9,000 to build and is adequate for black-hole simulations which would otherwise cost $6,000 per run on a conventional supercomputer. The black hole calculations are not memory-intensive and are highly localizable, and so are well-suited to this architecture. Khanna claims that the cluster's performance exceeds that of a 100+ Intel Xeon core based traditional Linux cluster on his simulations. The PS3 Gravity Grid gathered significant media attention through 2007, 2008, 2009, and 2010. The computational Biochemistry and Biophysics lab at the Universitat Pompeu Fabra, in Barcelona, deployed in 2007 a BOINC system called PS3GRID for collaborative computing based on the CellMD software, the first one designed specifically for the Cell processor. The United States Air Force Research Laboratory has deployed a PlayStation 3 cluster of over 1700 units, nicknamed the "Condor Cluster", for analyzing high-resolution satellite imagery. The Air