What is the connection between jiffies and IPS? How to convert jiffies to IPS?

view story

http://unix.stackexchange.com – Reading from /proc/PID/stat a lot of information can be processed. I would like to see how many percentages has been used of CPU power by this process. There are a lot of variable around here (utime, stime, cutime, cstime, gtime, cgtime) but they are in jiffies. The problem with this that jiffy depends on speed of the current CPU. However IPS (Instructions Per Second) depends on inctructions set, and which program do we run but maybe this is more accurete. I would like to use this information in embedded systems where I could pick a CPU that just satisfies the features. In this way I don't ha (HowTos)