I just picked up a 27" iMac. Just for kicks I ran Blackmagic on all the drives. The two surprises were the slow SSD and super-slow FireWire 800 speeds. The FW800 is connected to a Promise SmartStar DS4600. I have been using this RAID for Time Machine via eSATA on my now-expired Mac Pro. The FW800 speeds are abysmal (28/44 MB/s). I guess it will still work as a Time Machine device, but wow, what a drop in performance! Next, I ran a test on the Apple-installed 256GB SSD. Again, the speeds are poor (181/214 MB/s), barely besting the 2GB internal HDD (143/146 MB/s). Now, on the other hand, my new external Promise Pegasus R4 RAID, connected via Thunderbolt is awesome! Check out these numbers! (505/476 MB/s) Just to be sure my older Promise SmartStor connected via FW800 wasn't a fluke, I connected it using USB 2. Not good.... (10/26 MB/s) Shouldn't the SSD perform a bit better, even for a SATA II device?