Double performance in synthetic benchmarks, when using OverflowAction=Block

Maybe the reason is that the DotNet Task Dispatcher is very good at giving high priority to dedicated threads running at full speed, thus delaying the handling of timer-events. There was actually a bug in dotnet 6.0.000 where the DotNet Task Dispatcher would never schedule timer-events as long other thread-task was pending. This was improved a little with Dotnet ver. 6.0.400, but timer-events still seem to have lower priority.

This means that if having 2 thread spinning hard, then it will delay the scheduling of the background timer-event, thus their spinning will actually introduce an unwanted "pause". But when reducing the spinning, then it will also reduce the "pause"-effect. Seems the SpinCount upgrades to Sleep(1) after 20 iteration, which makes the "pause" even harder.

It is strange that timer-event are not scheduled when actually having more physical cores (4) than active threads (2). So maybe I'm experiencing something else.