There right now is not enough info about the Fusion drives to give you a yes or no. There is about a 50/50 shot that you might be able to do this. Also this fusion drive thing is not all that new There are HDD that are the same way, but Apple is just making the largest drive like this right now.
Probably not. See http://support.apple.com/kb/HT5446 and http://www.anandtech.com/show/6406/understanding-apples-fusion-drive for starters.27" i7 iMac SL, Lion, OS X Mountain Lion (10.8.2), G4 450 MP w/Leopard, 9.2.2
Any updates on this matter? I have been trying to find out if it is possible and there are two blogs that has caught my attention but they seem so contradict each other:
Patrick Stein says it works:
OWC says it doesn't:
Currently Being ModeratedApr 30, 2013 12:03 PM (in response to wschmid123)
I do not know whether you will be able to upgrade. However, a fusion Drive is not the same as a hybrid drive. A hybrid drive uses the solid state storage as a temporary cashe. Information must be pulled from the hard drive the first time it is requested and every time it is requested later if the computer has been rebooted. Information must be written back to the hard drive before the computer can be shut down. Regularly used files are never "permanently" stored to the SSD. The Apple Fusion Drive keeps track of those files, including the operating system, which are used the most and moves those to the solid-state portion, where they will continue to reside as long as they continue to be a priority.
I do not know whether you will be able to upgrade. However, a fusion Drive is not the same as a hybrid drive. A hybrid drive uses the solid state storage as a temporary cashe.
That is not true of the Seagate Hybrids (most of the hybrids are Seagates) The SSD section is (semi) permanent. Regularly used files live on the SSD, less regularly used ones may be moved back to the HDD to make room for new files. This not a cache, it is the same method used by the Fusion Drive, (but with more SSD space there is less moving of files). The Hybrid also have a cache, it is 32MB or 64MB of Ram, located on the drive as part of the drive controller, it is a true cache (read/write) using a variant of the LRU algorithm.