6 Replies Latest reply: Jul 5, 2013 1:28 PM by Hamiditized
ajackson88 Level 1 Level 1 (0 points)



This might be a little too soon to ask, but I just have to ask:


Does anyone know if the 'Fusion Drive' will function on a dual-boot machine via Bootcamp with Windows? Or even on a new iMac running only Windows?




Andy Jackson

  • Rudegar Level 7 Level 7 (23,620 points)

    doubt the operating system is even aware of the drive being anything but a std hd

    it's not really apples invention they are already around by other names


  • Liquid Rhino Level 1 Level 1 (75 points)

    As per Anandtech, it doesn't seem to be a typical hybrid drive per se, rather an OS X software-level function controlling a separate 4GB buffer on the SSD (the 'fusion' part) that controls writes over two separate drives (the SSD & the HDD).


    "The Fusion part comes in courtesy of Apple's software that takes the two independent drives and presents them to the user as a single volume."


    and later:


    "With Fusion Drive enabled, Apple creates a 4GB write buffer on the NAND itself. Any writes that come in to the array hit this 4GB buffer first, which acts as sort of a write cache. Any additional writes cause the buffer to spill over to the hard disk. The idea here is that hopefully 4GB will be enough to accommodate any small file random writes which could otherwise significantly bog down performance. Having those writes buffer in NAND helps deliver SSD-like performance for light use workloads.

    That 4GB write buffer is the only cache-like component to Apple's Fusion Drive. Everything else works as an OS directed pinning algorithm instead of an SSD cache. In other words, Mountain Lion will physically move frequently used files, data and entire applications to the 128GB of NAND Flash storage and move less frequently used items to the hard disk. The moves aren't committed until the copy is complete (meaning if you pull the plug on your machine while Fusion Drive is moving files around you shouldn't lose any data). After the copy is complete, the original is deleted and free space recovered."


    See complete article here:



    hope this helps

  • Joe Gramm Level 5 Level 5 (6,315 points)

    Apple has posted this KB Article about the Fusion Drive. It states the HD portion can have two partitions. The partitions can run both OS X and Windows using Boot Camp. The exception is the 27" iMac with a 3 TB Fusion Drive.

  • rmiller88 Level 1 Level 1 (70 points)

    I believe that when you add a second partition, it lives only on the standard hard drive and not the SSD. You can only add Bootcamp to this partition. This means that you can run Bootcamp, but it will not get any advantage from the SSD (it won't even know it exists).

  • Vuddha Level 1 Level 1 (0 points)

    Then the Question arises Can you Add Bootcamp to The 768 SSD??

  • Hamiditized Level 1 Level 1 (0 points)

    This seems to indicate that it is indeed possible to add just one Windows partition to a Fusion drive (using Bootcamp, not Disk Utility), and use it to dual boot into Windows (the partitino will physically reside on the Hard Drive, not SSD):