POWER7

POWER7 is a family of superscalar multi-core microprocessors based on the Power ISA 2.06 instruction set architecture released in 2010 that succeeded the POWER6 and POWER6+. POWER7 was developed by IBM at several sites including IBM's Rochester, MN; Austin, TX; Essex Junction, VT; T. J. Watson Research Center, NY; Bromont, QC and IBM Deutschland Research & Development GmbH, Böblingen, Germany laboratories. IBM announced servers based on POWER7 on 8 February 2010. IBM won a $244 million DARPA contract in November 2006 to develop a petascale supercomputer architecture before the end of 2010 in the HPCS project. The contract also states that the architecture shall be available commercially. IBM's proposal, PERCS (Productive, Easy-to-use, Reliable Computer System), which won them the contract, is based on the POWER7 processor, AIX operating system and . One feature that IBM and DARPA collaborated on is modifying the addressing and page table hardware to support global shared memory space for POWER7 clusters. This enables research scientists to program a cluster as if it were a single system, without using message passing. From a productivity standpoint, this is essential since some scientists are not conversant with MPI or other parallel programming techniques used in clusters. The POWER7 superscalar multi-core architecture was a substantial evolution from the POWER6 design, focusing more on power efficiency through multiple cores and simultaneous multithreading (SMT). The POWER6 architecture was built from the ground up to maximize processor frequency at the cost of power efficiency. It achieved a remarkable 5 GHz. While the POWER6 features a dual-core processor, each capable of two-way simultaneous multithreading (SMT), the IBM POWER 7 processor has up to eight cores, and four threads per core, for a total capacity of 32 simultaneous threads. IBM stated at ISCA 29 that peak performance was achieved by high frequency designs with 10–20 FO4 delays per pipeline stage at the cost of power efficiency.