Quote:
Originally Posted by PMF Media
I assume you copied that info from the computers system profile (report), seems strange to me that the fusion drive would appear as 2 separate drives rather than the 1 "fusion" drive, what appears an your desktop as the mounted system drive? As I don't have an iMac with a FD I'm not sure of the exact behaviour within the MacOS -= perhaps someone else can chime in here  |
I will chime in here.
A Fusion Drive is two physically different disks. One is your typical spinning disk and the other is an SSD. The two drives are fused together (hence the name) with a virtualization layer that Apple calls Core Storage. The virtualization that Core Storage provides allows for an abstraction of what is really going on with a Fusion Drive. This abstraction is what allows the user and applications to see the Fusion Drive (remember, 2 disks) as a single drive and treat it as such.
Since Core Storage presents the Fusion Drive to Pro Tools (or anything else) as a single drive, the performance benefit of a dedicated SSD is lost. Pro Tools has no way of knowing which portion of the Fusion Drive is the SSD portion. This is why you run into disk speed issues with a Fusion Drive. The probability is high that Pro Tools will try to record to the slower spinning disk portion of the Fusion Drive.
The Mac OS will figure out what data is most often used and move it to the SSD portion. It cannot make Pro Tools use only the SSD portion.
Core Storage is also what makes FDE (full disk encryption) possible with Lion OS and later.
Note that the version of Disk Utility that ships with a Mac that has a Fusion Drive is different from the version of Disk Utility that ships with all other Macs. You must use the version of Disk Utility that came with your Fusion Drive.