Benchmark tests for sw tools
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I
am seeking to implement some benchmark tests measuring the performance of a software tool. To get 100% reliability, the best solution could be getting the number of clock cycles each operation takes, however due to different processor's architecture, this becomes invalid to run across different machines.
I need to have a generic mechanism that could run on any machine and be time independent. I though of running some basic linux commands and get the avg execution time and get the cpu time the operation in my SW will consume and then divide the 2 times, 

I mean the time of executing the linux commands will give me indication how much the runninh machine is loaded and dividing 2 times , i get a relative value 

Let me know your thoughts about this. Do you think such a mechanism will be reliable ?