Chosen Solution
So I followed the complete guide (and followed it in reverse) to insert the Dual Drive into my Macbook Pro. But when I power my Mac, it won’t recognize the SSD that is inside the Dual Drive enclosure. It doesn’t show up on Disk Utility and doesn’t show up in Startup Manager either (pressing ⌥ at startup). I haven’t tried to connect the drive directly to my Mac through USB yet. The SSD in question is the Crucial BX100 250GB.
First make sure your systems firmware is upto date. Follow this Apple T/N: About EFI and SMC firmware updates for Intel-based Mac computers. If your firmware is upto date your system may not support your SSD in the optical drive carrier. Most SSD’s today have an auto setting SATA port. But, some MacBook Pro’s have problems with these drives as the optical drives SATA port is somewhere inbetween SATA II & SATA III. Sadly trying to find a fixed SATA II (3.0 GB/s) SSD is getting difficult.
SOLVED : Samsung EVO 850 SSD SATA III working in Optical Drive now. MacBook Pro (15-inch, Early 2011) - 2.2 GHz Intel Core i7. I have SSD as main drive and a HDD in “Optical Drive”, But it was taking too much battery/ too much noise. I put a new Samsung 860 EVO 500GB SATA III SSD in optical drive. For some reason it was not showing anything !!! After reading some post , I realized that my caddy is not SATA III compatible. So I clicked on the link provided https://www.amazon.com/gp/product/B004FM… It looked exactly like my previous caddy but something inside, a chip or something is new. Make sure seller is “HIGHFINE”. NOTE : After installing new Caddy in optical drive with SSD Sata III, I started computer and was able to see SSD in DISK UTILITY. I initialized/ formatted it. BUT drive was showing in some weird small size. I restarted Laptop and it came on FINE.
