Recently, I am using tools such as Vtune or likwid, But I get confused by event "CPU_CLK_UNHALTED.CORE" and " CPU_CLK_UNHALTED.REF". I have found official definition
"CPU_CLK_UNHALTED.CORE" : Core cycles when core is not halted
" CPU_CLK_UNHALTED.REF": Reference cycles when core is not halted.
What's the difference between core cycles and reference cycles?
Thank you for your help!