fliptw wrote:Wrong. All modern desktop CPUs are RISC chips, on Wintel platforms they include decoders that convert from x86 CISC instructions to their RISC equivilants.
Wheather a Chip uses CISC or RISC has no bering on the degree of specialization.
Excuse me, but all AMD and Intel processors are CISC. What do you think MMX, MMX2, SSE, SSE2 are if not additional, specialised instruction sets?
You are referring to the possibility that all these instructions are micro-coded in terms of a reduced instruction set, but that isn't the case. The best proof is that some of the multimedia instructions require special registers (e.g. 96 or 128bit wide) which are definitely implemented in hardware in the processor.
The only desktop processors that are RISC are those found in Apple computers.
You are correct, of course, when you say that RISC or CISC does not determine the field of application of a processor. However, it does indirectly. CISC is slower than RISC (especially so if the instructions are microcoded on a lower level). So RISC is the natural choice when power is important and the field of application is narrow.