I have similar issues with a M1 Max MBP 16” 64GB with Eastwest Opus. I can have the issue with only 1 or 2 tracks, loading a patch from the orchestral libraries, and then on the first notes (play live or play from the sequence), I will have one core quickly spiking and then going down… and then if I try again, it could be fine, no spikes at all… and then later on I come back to the track and bam, it will spike again. Also in Logic with Rosetta. Also, it’s happening with all samples on the internal 8TB SSD, so it shouldn’t be a bandwidth issue from the drive, and it shouldn’t be a memory issue either since I had 64GB and it happens with only couple of tracks and very little use… so I really wonder if it’s not because of the Rosetta conversion. I tried to start Logic in native, but I couldn’t confirm the issue… it’s happening with 256 samples latency. I wonder if anyone else has this problem… I was starting to think it was just Opus (nice ‘Play’ didn’t had good reputation in the past). I never used Opus before, so I can’t compare with previous mac. Any feedback is welcome, and I hope mine will help you in some way…