Following up on my little SSD series, today I finally got my Seagate GoFlex thunderbolt enclosure from customs. The SSD arrived around two weeks ago, and I had already done a SuperDuper copy of my home-made Fusion drive to the SSD via USB 2.0. Three days later, I could start using it, via USB. First I preferred the extra speed from my Fusion drive, but pretty soon I took the quiet of the SSD over those extra MB/sec.
Speed-wise I was surprised to find I would get about 34 MB/sec via USB 2.0. I guess I under-estimated USB 2.0 a little bit, assuming I would get ~20 MB/sec. The Fusion drive solution would give me bursts of 114 MB/sec write and 180 MB/sec read, but over time I would often get around ~30 MB/sec. I must admit I had forgotten exactly how slow magnetic disks can be, I assumed I would get around ~80 MB/sec from it, but I was wrong. So resolving my over-estimating magnetic disk speeds and under-estimating USB 2.0 speed and enjoying the quiet, the last week was spent running of the SSD via USB. That meant that taking it out of the USB dock and into the GoFlex thunderbolt adapter took a few seconds and I could boot.
I’m sure you guessed it, as had I, but wow! Thunderbolt is fast! Even though I knew it only performed a bit more than half as quick as what the disk is capable of, starting up Photoshop was 7 seconds (vs 23 seconds before) and other apps are similarly responsive. Using Lightroom is soo much smoother. :-)
The final result was that I’m getting a pretty consistent 355 MB/sec write and 383 MB/sec read of the disk, which is better than the 330 MB/sec I was expecting, but far from the 550 MB/sec the disk can deliver. I still have found no answer to why all those enclosures won’t push the disk speed further, even Thunderbolt 1 has bandwidth to spare at this speed. But since I knew that going in, all in all I’m very happy. :-) And hopefully, this is where my SSD story ends, until I’ll transition to my next iMac in two CPU generations time.