Chosen Solution
I just installed a Crucial C300 in my mac mini using the Mac Mini Dual Hard Drive Kit. While cloning the HDD to the SSD using CarbonCopyCloner (which I’ve used successfully multiple times on a MacBookPro and a MacPro), the SSD suddenly disappeared and won’t show until a 10 minutes “cooldown”. I then tried to copy 4Go files to the SSD from the HDD, and every 10 seconds the copy stalls for 30 seconds. Can it be a faulty cable? or is it a Sata speed issue (as seen on some MacbookPro using 3G data SSD)? EDIT: I’ve tried with another SSD (a Crucial M4 and a Samsung 840) , and it worked perfectly. So it seems that the Crucial C300 is not “supported”
It may be unsupported or just a bad drive. Contact Crucial to see if the drive is supported.