I am an Assistant at a College and a few of our systems are having an issue. When you hit play Avid does not begin playing for around 2 seconds. We are on Avid 8.6.1 and run on Yosemite version 10.10.5
The audio in the timeline is synced and if you scrub through or nudge the playhead frame by frame the audio is synced. It is when we hit play that it has a 2 second delay before it begins and then all of the audio is off by 2 seconds or so.
Avid system settings are on default and when observing work load in the Activity Monitor the CPU, Memory, Energy, and Disk areas all show vast amounts of room for more processes to be occur at that time.
Your system specs are incomplete. The hardware is not near as important as the software. Are you using a video input/output device such as a Black Magic Ultrastudio? You might have the wrong driver version. Are you using a version of Mac OS that is Avid certified? You can also run a permissions repair on your system drive and repair disk on your media drives if they are not shared storage. Local drives only. Also rebuild all your media databases.
Most slowdown issues are incompatible combinations of software and drivers or some minor file or software corruption. Also, some antivirus software can cause these kinds of issues.
Media Composer works well when you have an install that meets the correct specs.
Online Editor / Colourist
We have an Avid CoreAudio Device and Avid MBox mini. The dongle is plugged in with a direct pathway to the computer systems. The Mac OS system works where the drivers are automatically installed with OS installation. As far as I can find, 10.10.5 of OS X Yosemite has no other drivers outside of the regular installation ones.
We have tried verifying and repair the disk locations of the various drives. We tested two different external drives and they had the same problem. We tried several drives on our school server and it has the same problem. We thought that maybe the Avid system had a corruption during download so I went and completely uninstalled Avid Media Composer and reinstalled it to see if that would help, but it did nothing. Mind you, we have the exact same set u on the other 22 IMac computers in this lab.