RC5, Leistung und FSB...

Zitat von r2g2

jep nur Cpu zählt bei Rc5. fsb ist komplett wurscht

Zitat von h4de5

nicht zu vergessn, die tatsache das a p4 egal wieviel mhz in rc5 *******e is

Zitat

RC5 involves a large number of integer additions, rotates and XORs. It doesn't require floating point calculations and won't, in general, benefit from them. There has been quite a lot of recent discussion on whether or not it might be possible to boost keyrates (on x86 architectures at least) by taking advantage of the fact that there are separate pipelines for integer and floating point instructions. (We leave it to the reader to figure out how to do floating-point XORs and rotates!)

Currently none of the clients attempt to make use of FPUs and we believe any use of the FPU will result in slower clients rather than faster ones. At least one bright person has suggested this is not necessarily the case and indeed he may be right. If anyone can develop an RC5-72 core that takes advantage of the x86 FPU for an overall client speed boost we would be very interested in hearing from them! If you are interested in looking into it the x86 core code is available and can be downloaded from http://www.distributed.net/source/.

Zitat

Integral to the mathematics of the RC5 algorithm are 32-bit rotate operations.
For whatever reason, the designers of the IA32 (32bit Intel x86) and the PowerPC architectures decided to implement the rotate function as a hardware instruction.

Many other CPUs do not have built-in hardware rotate instructions and must emulate the operation by (at the very least) two shifts and a logical OR. This handicap is why many non-32bit-Intel [1] and non-PowerPC computers run RC5 slower than one might expect based on real-world benchmarks. It is also the main reason why the RC5 client is a poor benchmark to use in determining the speed or performance of a particular CPU.

[1] The IA32 architecture is that used by the Intel 80386, 80486, Pentium, Pentium Pro, Pentium II, Pentium III and Pentium 4 processors. The Pentium 4 does not however have a hardware rotate instruction.