performance impact calculation in Vtune

[vtuneuser]

The formulas in Vtune to calculate the performance impacts of some of HW events have the constant factors, how those factors were determined? for example,

Level1CacheLoadMiss Performance Impact = ((1st Level Cache Load Misses Retired*10)/Clockticks)*100

Level2CacheLoadMiss Performance Impact = ((2ndlevel cache load misses retired *(15*(ProcessorSpeed/BusSpeed)))/Clockticks)*100

Where the constant "10" or "15" came from?

Thanks

[David_A_Intel1]

Hello vtuneuser!

Another good question! If you look in the online help for a topic title "About Counter Interpretation", you will see this sentence:

"The knowledge and advice in this section was developed from the experience of Intel's performance engineers."

In general, the constants were derived by Intel engineers doing performance tuning. I'm sorry that it is not easier to locate this info.

Regards,