Chosen Solution
I’m considering replacing my optical drive in my mid 2007 iMac 20" (EMC 2133) with a hard drive. I have already replaced the internal hard drive with a SSD and would like to add more internal capacity. My question is two-fold: Is there any size limit for the hard drive going into the optical bay? I understand this bay uses PATA (at least from my searching thats what I’ve found). and secondly, I use this computer for audio recording and production so the drive going into the optical bay will be used mostly for 24 bit audio files which get pretty big. Will I have issues with slower speed of PATA (if it is indeed PATA in this bay) keeping up with streaming multiple high res audio files in real time?
Personally I would opt for reversing your plan. Put the boot OS on the optical bay (or an external) drive and do your recording to the SSD. The optical, or external drives will not perform as well for audio recording (if that’s what you’re doing). If this answer is acceptable please remember to return and mark it accepted.
The optical bay adapter indeed connects via PATA. But it accepts accepts 2.5 inch SATA hard drives up to 9.5 mm in height. See the specs here: 12.7 mm PATA Optical Bay SATA Hard Drive Enclosure You might even consider a hybrid drive: 1 TB SSD Hybrid 2.5" Hard Drive
