Sunday, November 23, 2008
RISC
In the mid-1980s to early-1990s, a crop of new high-performance RISC (abridged instruction set computer) microprocessors appeared, which were initially used in special reason machines and Unix workstations, but then gained wide receipt in other roles.
The first commercial design was released by MIPS Technologies, the 32-bit R2000 (the R1000 was not free). The R3000 made the design truthfully practical, and the R4000 introduce the world's first 64-bit design. Competing projects would result in the IBM POWER and Sun SPARC systems, respectively. Soon every major vendor was releasing a RISC design, counting the AT&T CRISP, AMD 29000, Intel i860 and Intel i960, Motorola 88000, DEC Alpha and the HP-PA.
Market forces have "weeded out" many of these designs, with almost no desktop or laptop RISC processors and with the SPARC life form used in Sun designs only. MIPS is first and foremost used in embedded systems, particularly in Cisco routers. The rest of the original crop of designs have disappeared. Other companies have attacked niches in the market, notably ARM, originally future for home computer use but since focused on the entrenched processor market. Today RISC designs based on the MIPS, ARM or PowerPC core power the huge majority of computing devices.
As of 2007, two 64-bit RISC architectures are still produced in volume for non-embedded applications: SPARC and Power Architecture. The RISC-like Itanium is produced in lesser quantities. The huge majority of 64-bit microprocessors are now x86-64 CISC designs from AMD and Intel.
The first commercial design was released by MIPS Technologies, the 32-bit R2000 (the R1000 was not free). The R3000 made the design truthfully practical, and the R4000 introduce the world's first 64-bit design. Competing projects would result in the IBM POWER and Sun SPARC systems, respectively. Soon every major vendor was releasing a RISC design, counting the AT&T CRISP, AMD 29000, Intel i860 and Intel i960, Motorola 88000, DEC Alpha and the HP-PA.
Market forces have "weeded out" many of these designs, with almost no desktop or laptop RISC processors and with the SPARC life form used in Sun designs only. MIPS is first and foremost used in embedded systems, particularly in Cisco routers. The rest of the original crop of designs have disappeared. Other companies have attacked niches in the market, notably ARM, originally future for home computer use but since focused on the entrenched processor market. Today RISC designs based on the MIPS, ARM or PowerPC core power the huge majority of computing devices.
As of 2007, two 64-bit RISC architectures are still produced in volume for non-embedded applications: SPARC and Power Architecture. The RISC-like Itanium is produced in lesser quantities. The huge majority of 64-bit microprocessors are now x86-64 CISC designs from AMD and Intel.
