I can't specifically comment on the iMac since I have a Mac mini with 16GB of RAM, a 2.6GHz i7 quad core processor, and a fusion drive. I LIKE IT
. It took a while, several days maybe, for the system to learn what my most frequently accessed files and applications are and sort out what files go where between the SSD and HD. Now as a practical matter, my average disk I/O performance approaches that of a pure SSD. Safari, Mail, NeoOffice, and other applications that I use daily load almost instantly and as an added fillip, the system is almost completely silent. (I say as a "practical matter
" as I have not run any extensive disk I/O tests and I am not sure there are any that would accurately reflect the individual user's peculiar use pattern.) FWIW I wouldn't part with the fusion drive on my Mac mini.
All is not beer and skittles however. There are some things Fusion drive users need to be aware of…
- The version of Mountain Lion that ships on Fusion Drive equipped Macs is not the same as the regular or App Store version of the OS. As far as anyone can tell the primary difference is a Fusion drive aware version Disk Utility.
- Fusion drive equipped Macs will NOT boot from a non-Fusion drive build of Mountain Lion
- The 10.8.5 update works with either the fussion drive or non-fusion drive builds but does not merge the two build threads.
- While Diskwarrior, Drive Genius, and TechTool Pro have been "certified" for use on Fusion drives some of their functionality is not recommended for use with Fusion drives.
- Checkmate is compatible with Fusion drives but it tests only and has no repair functionality. When it runs surface scans it scans the SSD and associated HD as physically separate entities — which they are.
These temporary restrictions are things I can happily ignore in exchange for the great system performance.