Posted by Justin on February 18 2026, 7:07pm:
each time the scheduler goes to run a thread, it might pick a different physical core. so each thread might be using a combined 100% of a core, but it could be distributed across 2 or more cores.
Posted by PThread (83.30.239.x) on February 19 2026, 4:37pm:
Unless the program sets thread affinity, in which case - depending on the system - it can significantly improve performance, especially with the current split between P-cores and E-cores, which Reaper happens to struggle with.
Posted by Justin on February 19 2026, 10:50pm:
thread affinity is a double-edged sword, and can cause a lot of other problems.
Posted by PThread (83.30.240.x) on February 21 2026, 8:28am:
True - however, for now Reaper can't fully utilize all cores, because P‑cores and E‑cores have different capabilities. It's not just an Reaper problem; awareness of hybrid CPUs is still limited.
Posted by Justin on February 25 2026, 1:15am:
That's not entirely true, if the OS is aware of the e-core vs p-core, and the DAW sets the priority level of its threads, then the scheduler can in theory do the optimal thing. I'm not sure of how well it works on Windows, but on macOS the OS does a great job.
Posted by Justin on February 25 2026, 1:16am:
(though to get it to work properly on macOS, we had to get our audio worker threads marked as realtime in the correct way, which was a bit of a fuss!)
