I recently replaced my broken SuperDrive with an OCZ Agility 3 120GB SSD with the following specs:
- 2.5" SATA 6Gb/s
- SandForce 2281 Controller
- Read 525Mb/s
- Write 500Mb/s
- 85K IOPS
I have an Early-2009 24" iMac (9,1), and I purchased a caddy to place the drive in in order that it can sit where the SuperDrive was.
My iMac has a SATA2 bus, but after connecting the SSD it will only connect at SATA1 speeds. I knew that the SuperDrive used to use this speed, but accepted that it was because is was simply an optical drive that could not push the speeds to saturate a SATA1 controller, so why bother with anything better.
However I expected the SSD to link at the SATA2 speeds that the bus supports.
I have the latest firmware on the drive itself, and on my Mac, I have reset my PRAM, and I don't know what to do next. Why does the SSD not connect at SATA2?
I accept that I cannot get SATA3 like the drive supports, but some initial testing using a disk speed test tool suggests I am only getting just over 100Mb/s write and 145Mb/s read, which is a mere 20-80% more than the regular drive gets.
I cannot just swap the drives over, as it's not like the MacBook Pros that use 2.5" drives. I have done a lot of Googling that suggested a firmware fix for MacBook Pros solved the same issue on those machines, but no luck for my iMac.
I have just put a normal SATA2 drive into the optical caddy, and it comes up at 3Gb (SATA2) just fine. So it seems it's something about the SSD that it doesn't like. Controller? I wouldn't have thought that it cared what was connected, so long as it was SATA?