[Southsidemusic]

Do you record to a secondary hard drive as needed and what deives are in the macs now. Very important as that might be the issues here.

And the 4GB is 4GB too sparse as PT12 need atleast 8GB or 16 recommended.

So the Macbook might be used for other stuff as it is an older slower computer and i would spend my time getting the imac working for PT rather than buying more RAM and new hard drive for the OS on that one.

So, hard drives inside and hard drive for recording?

And the iMac, is it a fusion drive inside as OS drive and no recording drive then thats the problem. Fusion drives are hell for Pro Tools and if you dont use a secondary drive for recording on any of the macs it is another addon for problems.