IBM PowerPC 604, 604e and 604ev processors
Introduction: April 1994 (604), 1996 (604e), June 1997 (604ev)
The PowerPC 604 was introduced in 1994 alongside the 603 and was designed as a high performance chip for workstations and entry level servers and as such had support for symmetric multiprocessing in hardware. The 604 was used extensively in Apple's high end systems and was also used in in Macintosh clones, IBM's low end RS/6000 servers and workstations, accelerator boards to Amigas and as an embedded CPU for telecom applications.
The 604 is a superscalar processor capable of issuing four instructions simultaneously. The 604 has a six stage pipeline and six execution units that can work in parallel, finishing up to six instructions every cycle. Two simple and one complex integer units, one floating point unit, one branch processing unit managing out-of-order execution and one load/store unit. It has separare 16KB data and instruction L1 caches and a 32/64 bit 60x memory bus, reaching up to 50MHz.
The PowerPC 604 had 3.6 million transistors and was manufactured by IBM and Motorola on a 0.5 µm fabrication process. The die was 196 mm² large drawing 14-17W at 133MHz. It operated at speeds between 100 and 180MHz.
The PowerPC 604e was introduced in 1996 and added a a condition register unit and separate 32KB data and intruction L1 caches among other changes to its memory subsystem and branch prediction unit, resulting in a 25% performance increase compared to its predecessor. It had 5.1 million transistors and was manufactured by IBM and Motorola on a 0.35 µm fabrication process. The die was 148 mm² or 96 mm² large, manufactured by Motorola and IBM respectively, drawing 16-18W at 233MHz. It operated at speeds between 166 and 233MHz and supported a memory bus up to 66MHz.
The PowerPC 604ev, 604r or "Mach 5" was introduced in 1997 and was essentially a 604e fabricated by IBM and Motorola with a newer process, reaching higher speeds with a lower energy consumption. The die was 47 mm² small manufactured on a 0.25 µm process drawing 6W at 250MHz. It operated at speeds between 250 and 400MHz and supported a memory bus up to 100MHz.
While Apple dropped the 604ev in 1998, in favour for the PowerPC 750, IBM kept using it in low end RS/6000 computers for several years.
Source: Wikipedia, the free encyclopedia.