Hi, I have a late 2012 iMac with a 1TB Fusion Drive. As the HDD had a lot of errors and my system became very slow and freezed a lot I decided to replace the HDD for a Samsung 850 Evo 1TB. Now I have 128GB PCI-ssd (Flash) and Samsung 850 EVO 1TB. I do have to say, that I am now quite convinced about the Fusion technique. With a much faster SSD, I dont feel any difference with my old FUSION combo HDD. So Apple did really a great job with the fusion technique. Although I still prefer SSD, because HDD break down every 2/3 years, and in Bootcamp Windows, everything is much faster. (windows dont recognize Fusion) Once installed the SSD, it got automatically fusioned with the PCI-ssd. On my Mac its all pretty and well. But I use Windows a couple times a week, and when I try to make Windows with Bootcamp, all I could select was 105GB (out of 1,12 GB) After installing, I noticed that Windows isnt seeing the 1TB Samsung 850 EVO at all! Thats also the reason why I could only get 105GB for Windows. Anybody any idea what I did wrong? I rather have 300GB for Windows than the 105GB that I have now.