[mr2000jp]

i hear that the cpu of the psx ,DC ,... is a (risk ) what does it mean and what is the pc cpu (intel pIII or amd athlon...) technology and whats the main deffirence between them ?
i dont know where or whom to ask so i posted it here , i thought may be ill get
help from you guys.

 

[SimonMallion]

I think it's: RISC, Reduced Instruction Set something.

 

[Guest]

I am not sure what differences in the technologies are between the Intel/AMD CPUS and Dreamcast RISC CPU. But I do know that the RISC technology is pretty old, where as the others are quite new. RiSC stands for Reduced Instruction Set and the C is probably CPU, bu I'm not sure. RISC processors have been around since the 1980s. So, that tells you how old of a technology it is. More than that, like how it works as compared to the other two, I don't know. But I hope this sheds some light on it for you.
sincerely,
sx/amiga

 

[bobotns]

RISC-CPUs (like PSone and PS2 CPUs) are faster then CISC-CPUs (like pIII and Athlon). The CISC-CPUs have built-in instructions that accelerates the treatment of specific applications (like MMX for multimedia applications). RISC-CPUs can do those instructions, but in smaller instructions. For example: CISC needs 1 instruction to encode a video, RISC will need 3 instructions to do that (it's just an example!!).
But since RISC have a faster core, it's not a problem!

 

[RVWinkle]

Originally posted by bobotns
RISC-CPUs (like PSone and PS2 CPUs) are faster then CISC-CPUs (like pIII and Athlon). The CISC-CPUs have built-in instructions that accelerates the treatment of specific applications (like MMX for multimedia applications). RISC-CPUs can do those instructions, but in smaller instructions. For example: CISC needs 1 instruction to encode a video, RISC will need 3 instructions to do that (it's just an example!!).
But since RISC have a faster core, it's not a problem!

It's much more complex than that. First of all, RISC based CPUs aren't always faster than CISC based CPUS. It's all about the quality of the design. For a comparison you can look at cars. One can modify a car with a 4 cylinder engine and make it faster than some cars with a 6 cylinder engine.

And just because I want to make things even more confusing I'll state this, both the PIII and Athlon actually have RISC cores. They have a decoder layer that translates CISC instructions into RISC.

But the bottom line is, RISC is just a design philosophy. Your should probably worry more about the real-world performance of the parts.