What is unit of CPU speed?

Answer 1

Depends on the benchmark used to measure:

• KOPS or KIPS - measure of instructions executed per second
• MFLOPS - measure of floating point operations per second
• Whetstones - measure of overall floating point performance
• Drystones - measure of overall integer performance.
• Livermore loops - measure of computing and looping performance
• etc. etc.

Never measure CPU speed by the clock speed. Different architectures and implementations of the same architecture can give dramatically different speeds on real applications even with the CPUs running on the same clock.

One example of this occurred when Apple first started making Macs using the PowerPC. Power Macs could run in software emulation of the Intel Pentium Windows applications much faster than the existing PCs, even though the PCs operated on faster clock speeds and were running the code native.