I have a 5k iMac (Late 2014), I am running Logic Pro X 10.2.0, and when I get pretty far into my project (there are about 75 tracks), the player starts to lag and make this awful choppy noise. I'm running it in 1024 for buffer size, I am cleaning up the project every few minutes, I am deleting unused files from the audio bin I am even FREEZING the tracks, but NOTHING is working! I have a HIGH END computer- this surely shouldn't be happening? I've seen people with well over 300 tracks... I shouldn't be lagging at all. I go to the audio bin and select unused and have 1,966 regions, but it will only let me delete a few of them. I'm really confused. Can anyone teach me what I'm doing wrong because there is clearly something I'm missing. ????