An Application Performance Comparison of HPCx to

The results of benchmarking several popular applications on EPCC's Blue Gene/L service, BlueSky, are presented and compared with results from running on HPCx, a 1600 processor p690+ system (which is currently the main UK academic super-computing resource). The HPCx to BlueSky performance ratio is generally smaller than that expected from the clock frequencies and oating point unit architecture of the processors, and this is likely due to better memory bandwidth on BlueSky. The codes generally scale well on HPCx and on BlueSky. When considering other cost factors, such as hardware cost, power consumption and oor space, BlueSky has a large advantage over HPCx. This is a Technical Report from the HPCx Consortium c HPCx UoE Ltd 2005 Neither HPCx UoE Ltd nor its members separately accept any responsibility for loss or damage from the use of information contained in any of their reports or in any commu-nication about their tests or investigations.