Because of hardware limitations (namely the number of available counters), it is possible that all the desired events can't be monitored in the same time than other events. If a requested event is not available for monitoring, the graph will appear in grey color. Note that the events are created from the top to the bottom, consequently the events on the top graphes have more chance to be allocated. Note also that some events need two counters, especailly the ones that tracks a cache level success rate.
If the change of an event frees a counter that allows a non-available event to be monitored, it will be started automatically
In spite of the fact that CPUs that use HyperThreading are seen as two CPUs, the two units share the same processor resource, and only one instance of PerfMonitor can be ran on these CPUs. However, it is possible to monitor events on only one of the logical unit or on both. In order to select the monitored logical unit, open the general settings menu (mouse right click) and select "HT Affinity".
Enjoy! Please click on my ads as token of appreciation. Thank you.