Travis Downs (travis.downs.delete@this.gmail.com) on February 27, 2019 7:25 am wrote:
>
> You can reverse the behavior, showing the max value by setting W_MAX envvar to 1, like so:
>
> W_MAX=1 ./offset-test.sh
>
> If you have the chance to run the CoffeeLake test again like this I would be very interested.
>


I have done the test again on the Coffee Lake.

I have repeated it a few times without seeing anything except maybe a shift by about half cycle towards higher values. There was still no value over 10.


Then I opened a file manager and I have started to do random clicks on directories or files.

This caused immediately a few 18 cycle values, one precisely when I opened the file manager and a few others exactly when doing various clicks. Not all clicks had effects.


So I assume that this happens due to some interaction with the cache activity of the other threads. I still wonder why with the old microcode it happened so reproducible at certain positions even without much activity on the computer.



Like I have written in the other message, with W_MAX=1 and the old microcode there were some extra neighboring positions where the 18 cycle values appeared frequently, but not reproducible when the test was repeated.