Is true that depending on the simulation I'm doing sometimes just uses 5 to 10 cores but that as you said could be that just doesn't need more.
But when i first test it was exactly the 50% that's why was souspicious....
Well I tested again as you suggested, I tried different ways and I always get the same result. from 1m to 10m the usage was exactly the same 50% of the threads only at full power.
I tried to duplicate the events, to 20m to see if would grab some of the other thtreads with no luck.
I understand might be a complicated issue, it is not so critical to me either, I will just enjoy my espresso between simulations
just wanted to report it.-----------
I guess the problem has to do with the numa cores one of them is at 100% while the other is calmly resting.
image attached.