I am planning on replacing my Mac Pro 3,1 (Early 2008) with one of the Haswell iMacs, and part of the setup will include a Bootcamp partition for Windows. Among other decisions I have to make (such as the ever-problematic i5 or i7 and which GPU) is how I'm going to allot space for Windows. I'm pretty much set on getting the 1TB Fusion drive and plan on having an external HDD for large media files and general backup. As I said, I also want to have at least a small partition for Windows. As I understand it, an unaltered Fusion drive will only ever allow you to use the SSD portion for OSX, or essentially, "the Mac" side of the computer. The natural scheme for a Bootcamp partition would mean placing windows on a part of the HDD portion of the Fusion drive. I've read about people separating the two portions of the Fusion drive into their respective parts, but I'm not sure I want to do that. My main concern is that I would see a performance hit on the Windows side because it's being stuck with the slower 5400rpm HDD. Windows would get none of the advantages OSX sees with the SSD/HDD combination. Presently, I see my options as the following: Parition the iMac drive normally; OSX gets most of the Fusion drive and Windows gets a parition of the physical HDD with enough space for all its apps Partition the iMac drive normally like above, except Windows gets a partition only large enough for the OS itself and some extra space for swap and scratch files plus updates; all applications would go on an external 7200rpm drive Leave the Fusion drive alone for OSX and try one of the Thunderbolt / USB3.0 external HDD solutions people have reportedly used for Windows (8.1) The first option is basically me doing nothing special and trying not to worry about whether or not I could have done something differently. It's also the cheapest option. The second option would mean getting a second external HDD, but Windows programs would benefit from the faster drive while the Windows partition is left to its own devices. I even considered getting one of the SSD/HDD hybrid drives for this very solution, but that's not necessarily what I'll do. I don't even know if the third option is a possibility, plus it would mean a lot more money. I've read several threads both here on Macrumors and on Apple.com's forums about people using either external SSDs via Thunderbolt or HDDs via USB3.0 with Windows 8.1 (I'm not sure if it has to be the .1 update, though). I know an external SSD with enough capacity for everything I want to do with Windows isn't in my budget. There are a couple Thunderbolt external drives out there, but they are pricey. OWC sells what looks like a nice USB3.0 enclosure, and I could get it with drives pre-installed or separately buy whatever brand/type of drive I want and install them. And because it accommodates two drives it would mean having to use only one port on the iMac. I have issues with the third option which probably have more to do with my own nervousnous (?) about the concept. It seems to me that Mac Pro users like myself who can't afford or justify the costs of the nMP and forced to go with the iMac would be rejoicing at an external HDD solution for Windows. I don't see enough people shouting from the rooftops, "This is the way to go!" While I've read several accounts of people using some kind of external device for Windows on the iMac, I can't help but wonder: Can the iMac's ports handle that kind of regular, heavy use of data for an OS? I'm not making any kind of statement based on expertise, it's just a thought. I'm a bit paranoid when it comes to hardware failure. To boot, the idea of having more hardware I have to rely on because I use it, and not simply for backup like my only-occasionally used Time Machine drive, makes me more nervous about failure. Now, I know some of you will simply tell me to get the SSD-only upgrade for the iMac. It would require a whole other paragraph, but let's just say the storage capacity I'm expecting to need would require the larger SSD upgrades which simply aren't in my budget. So, does anybody have any thoughts on one of these setups? As I said before, there are still options related to what model I want to buy I have to figure out. Depending on those choices my budget may already be near its limit. Having to decide on the screen size is nerve wracking as it is!