Hi guys! I own a late 2012 iMac 27" with 3TB Fusion Drive. I'm into video editing (amateur at the moment but I'll turn professional in a few months), and I'll need higher writing and reading speeds, but without sacrificing storage. According to Blackmagic Test, my iMac currently has writing speed of 280 MB/s and reading speed of 350 MB/s. I've been reading quite positive reviews about the Samsung SSD 840 Pro (with speeds of both writing and reading above 500 MB/s), and I'm considering the following: 1. Replacing the internal 3TB HHD (just the HHD, not the unremovable Apple blade SSD) with a 256GB Samsung SSD 840 Pro. 2. Using the 3TB HHD as a external drive enclosed in the Seagate GoFlex Thunderbolt Adapter. 3. Fusing the three drives (I don't even know if this is possible, but according to some articles I read this might be feasible). So what do you guys think? Have any of you done something similar? Any suggestions/comments/feedback on this? Thanks in advance!