James Wilkinson wrote:
As processors have got faster, memory hasn't kept up. So a cache miss is proportionately much more expensive, and using cache effectively more important. You can even find people reckoning that x86 these days is competitive with RISC because it's effectively a compression mechanism for RISC code!
If you ask me, it is more like developers of RISC processors are loosing battle on the financial field. You can't really effectivly compete against giant such as Intel in very long term. And RISC processors vere competing against Intel for a very long time now.
RISC processors historicaly have more registers, multiple FPU and integer units, multiple cores (something Intel just started to implement) and so on... But they are lacking in some other areas and basically loosing frequency battle. And really, there is only so much that better design can do against higher frequency... Up until recently, frequencies of RISC processors were at about the same level as Intel processors (with exception of Alpha that was for one period of time way ahead of others on frequency front, but now has fallen way behind Intel). If RISC processor is double the speed than Intel processor at the same frequency, and Intel makes processor that runs at 3 or 4 times higher frequency, than obviously Intel is going to be faster... Not really a rocket science.
Don't forget that the CELL processor is supposed to be based on RISC. When it comes out, and if it supports Linux as some rumors state, then it will really shake up the computer industry. From some of the hype, it is supposed to be as fast as 4 top of the line pentiums.
Now IBM and Sony can compete against Intel. We will have to wait and see if the CELL is all hype or is actually as good as it is stated. The cost is supposed to be low enough to include in Cell Phones. Much lower than the cost of a top of the line P4.
PowerPC processors by some accounts are still the fastest but again, that would depend on the application.
I want to see a CELL processor in action. -- Robin Laing
