The POWER5 contains 276 million transistors and has an area of 389 mm2. It is fabricated by IBM in a 0.13 μm silicon on insulator (SOI) complementary metal–oxide–semiconductor (CMOS) process with eight layers of copper interconnect. The POWER5 die is packaged in either a dual chip module (DCM) or a multi-chip module (MCM). The DCM contains one POWER5 die and its associated L3 cache die. The MCM contains four POWER5 dies and four L3 cache dies, one for each POWER5 die, and measures 95 mm by 95 mm. Several POWER5 processors in high-end systems can be coupled together to act as a single vector processor by a technology called ViVA (Virtual Vector Architecture). POWER5+ The POWER5+ is an improved iteration of the POWER5 introduced on 4 October 2005. Improvements initially were lower power consumption, due to the newer process it was fabricated in. The POWER5+ chip uses a 90 nm fabrication process. This resulted in the die size decrease from 389 mm2 to 243 mm2. Clock frequency was not increased at launch and remained between at 1.5 to 1.9 GHz. On 14 February 2006, new versions raised the clock frequency to 2.2 GHz and then to 2.3 GHz on 25 July 2006. The POWER5+ was packaged in the same packages as previous POWER5 microprocessors, but was also available in a quad-chip module (QCM) containing two POWER5+ dies and two L3 cache dies, one for each POWER5+ die. These QCM chips ran at a clock frequency of between 1.5 and 1.8 GHz. Products IBM uses the DCM and MCM POWER5 microprocessors in its System p and System i server families, in its DS8000 storage server, and as embedded microprocessors in its high-end Infoprint printers. DCM POWER5 microprocessors are used by IBM in its high-end IntelliStation POWER 285 workstation. Third-party users of POWER5 microprocessors are Groupe Bull, in its Escala servers, and Hitachi, in its SR11000 computers with up to 128 POWER5+ microprocessors, which have several installations featured in the 2007 TOP500 list of supercomputers. IBM uses the POWER5+ QCM in its System p5 510Q, 520Q, 550Q and 560Q servers. Notes See also IBM System p IBM Power microprocessors PowerPC POWER6 References "IBM Previews Power5". (8 September 2003). Microprocessor Report. Clabes, Joachim et al. (2004). "Design and Implementation of the POWER5 Microprocessor". Proceedings of 2004 IEEE International Solid-State Circuits Conference. Glaskowsky, Peter N. (14 October 2003). "IBM Raises Curtain on Power5". Microprocessor