Quote: Originally Posted by robotpriest Here's a one minute long sample of a Cubase 6.5 session. The most frequent CoreAudio call comes in at a whopping "0.0%" frequency. The "coreaudio2asio" call takes up 1.3% of the cpu time. Most of Cubase's time is spent processing semaphores aka scheduling and locking which BTW is the same thing Logic is doing most of the time. The Cubase engine as coded for the Mac is what is broken here, not CoreAudio. LOL who said anything about core audio being broken ? Care to explain all of the other DAW hosts , I doubt they are using Steinis audio engine.