Boom. It is done. System Specs: Late 2012 27” iMac EMC2546 3.2 GHz Core i5 CPU 16GB 1600MHz DDR3 RAM Nvidia GeForce GTX 680MX 2GB DDR5 GPU Storage... see below What I started with: 1TB HDD partitioned as follows: 700GB for Macintosh HD 300GB for BOOT CAMP What I ended up with: 1TB HDD + 1TB SSD set up as follows: 1.5GB Fusion Drive (1TB + 500GB) for Macintosh HD 500GB pure SSD for BOOT CAMP Recovery Partition on SSD for speed and reliability Here is the output of “diskutil list” in Terminal: Disclaimer: This was absolutely horrible to do both on the software and hardware side. The adhesive strip design is ****ing retarded. EVERY air cooled computer will eventually need to be opened and cleaned. The glass is incredibly fragile, and if you break it you can go cry in a corner. Nobody is coming to help you now. Boot Camp Assistant is a terrible mother in law. Apple went to the DMV, looked at the personalities of the bureaucrats there, and said to themselves “YES, this is exactly what we want for Boot Camp Assistant”. I went down many one way streets trying to get this working, and below is the condensed version of what you have to do, hopefully without any one-way paths. Winclone messed up my Boot Camp partition requiring hours of restores. I don’t recommend touching it, use paragon instead. What you’ll need: SSD (duh) I used a Samsung 850 evo 1TB iFixit Adhesive Strip Set (don’t cheap out!) M.2 SATA to regular SATA kit. Alternatively there is this kit External Hard Drive big enough to hold the contents of “Macintosh HD” External Hard Drive big enough to hold the contents of “BOOT CAMP” (can be same drive as above) SuperDuper! (Alternatively Carbon Copy Cloner) Paragon Boot Camp Backup. I do NOT recommend Winclone! El Capitan Install, or other favorite Mac OS Two cans of canned air for removing all nasty dust (Sam’s Club has them for really cheap) Torx Bits Possibly a Windows Install USB drive (Winclone destroyed my Boot Camp partition which required me to run a CHKDSK that didn’t work, Restore to a Restore point, waste hours with all sorts of other crap). If you’re lucky you won’t need it. Helpful (not required): USB SATA Enclosure for SSD Wipes for display and thermal paste removal. I recommend these. Isopropyl Alcohol for removing old thermal paste Double-Sided Adhesive (I recommend something from 3M). Don’t use packing tape or something similar, get something serious. Plastic Spudger (Really Useful!) Thermal Grease/Paste, I recommend Arctic Silver 5. What to do: Get your external drive ready, and use Disk Utility to add a partition that’s large enough for at least your Macintosh HD folder (Journaled HFS+). If you plan on using this disk as your BOOT CAMP transfer disk, make the partition large enough for your BOOT CAMP files and your Macintosh HD contents (not necessarily drive). In my case I named it “Useful Drive”, as it served as a useful drive during this whole process. If you want you can simply use your Time Machine drive, as you’re basically making a backup (some would argue an even better backup than the Time Machine Backup), however going this route will destroy any historic changes. Use SuperDuper! to make an exact copy of your current Macintosh HD partition. While it is copying LEAVE YOUR COMPUTER ALONE. You’re copying a partition that’s actively being used, and changing any file in the copy process by doing pretty much anything will likely give you headaches you don’t want or need. It will take a good amount of time to copy, so go do something else. Restart your computer, and hold the “option” key to boot from your newly created disk. You will no longer boot from the partition on your HDD, unless something goes wrong. Make sure everything is working right on your newly created clone partition. Now you will create a backup of BOOT CAMP using Paragon Boot Camp Backup. You can save it anywhere you want except the internal HDD. I saved it in my Useful Drive. The software is a little confusing, as it automatically finds the boot camp partitions for you. Therefore you select a drive as a source and not a partition. (note: source not pictured) Once you’ve saved your copy of the Boot Camp partition the fun begins. Follow iFixit’s Guide on opening the iMac, and install your M.2 SATA to SATA adapter. Some guy has made an excellent video of the entire process that you can watch here. I recommend watching this in full before attempting the procedure. This step is optional, but I further recommend following their heat sink removal guide and re-applying the thermal paste which may have become cracked and less effective. This will also give you better access to remove any dust that has accumulated around the exhaust port. Make sure to reapply thermal grease to both the CPU, GPU, and GPU Memory. Here is iFixit’s guide on removing and reapplying thermal paste. The following picture shows the entire operating procedure. I used papers to keep all the screws organized, although screw organization really isn’t a problem. From the far side of the table down, you see the iMac resting in its operating position, the internal HDD, the PSU and its 4 torx screws, to the left of that is the fan. Then there’s the display with the speakers resting on the appropriate sides. To the right of the display are the 7 screws for the logic board. At the very bottom is the logic board with the heatsink removed. You can see the isopropanol and kim wipes, the spudger, and the paper towel that used to clean the spudger when removing the old thermal paste. Once you’ve got the heat sink back on the Logic Board, put it, and the Power Supply (PSU), back into the iMac, and hook up the PSU to the Logic Board. You’ll also have to connect the Power Button Cable to the PSU. Plug in the computer, and look on the logic board. You should see a green LED on the left side of the Logic Board. You may also hear your Power Supply making a faint ticking sound. This is normal. Now push the power button. This should cause all 3 or 4 LEDs on the Logic Board to turn on. Optionally you can plug in a speaker to hear the power up Chime. The first time I set everything up, the computer showed no signs of life. Pushing the power button did nothing. Removing and re-instlalling the M.2 SATA to SATA adapter and switching the SATA cable around got the computer to wake up again. This freaked me out, and I still don’t know the exact cause of the issue. I am including this information here to keep someone else from freaking out should this happen to them. If everything works (3 or 4 LEDs), hold the power button and turn off the computer completely. Don’t leave just the logic board and PSU on for too long, as there will be no fan providing cooling. Unplug the computer from the wall, and re-install everything by following iFixIt’s guide backwards up to removing the HDD. To install the SSD you will need to hook up the Power/SATA adapter (included in the kit) to the original HDD cable. Connect a power lead and the SATA lead to the HDD, and use the remaining Power cable, and the SATA cable from the M.2 adapter and attach those to the SSD. This all sounds convoluted, but should make sense once you get to this step. As an aside, I’m not sure if OS X cares which SATA port you use for the HDD or the SSD, but to be safe I went with the default configuration that apple uses (M.2 SATA --> SSD). There is extra space in the case for the SSD, but not much. I recommend sticking the SSD underneath the HDD in such a way that there is minimal metal to metal contact with the SSD and the HDD. It should sit securely, but I highly recommend adding some double-sided adhesive to the SSD and sticking it onto the case of the iMac. You’ll notice in the following picture a cable mess above the HDD that’s not in iFixit’s pictures. That’s the extra power splitter kinda squeezed in there. The SSD (not visible) is underneath the HDD. You may find your own solution for sticking the SSD in, but this is what I did. The thing to look for is 1. that there is enough room for the front LCD panel, and 2. that nothing moves around as you tilt the display or transport the computer. Now it’s time to hook up the front panel (but not with adhesive!) IMO this is the riskiest part of this whole procedure, as you can very easily crack the edge glass of the display and go cry in a corner. What you want to do is verify that everything is hooked up properly and recognized by OS X. You’ll want to have your keyboard and mouse handy. I used the cardboard box the iFixIt Adhesive kit came in to hold the display while it was connected. * Turns out I lied in step 3, you will boot one more time into your HDD. If at this point everything checks out (Speakers, Camera, Microphone, HDD, SSD, RAM), it’s time to properly re-install the front panel. Unhook it, place it face down on your towel or whatever, and follow iFixIt’s guide on re-installing the adhesives and front panel. I recommend using mega suction cups to lower the display, as I didn’t have use them and it’s .5mm slightly higher on the left side. I also scratched some of the black vinyl or whatever on the right side while lowering the front panel. Take a break, go to sleep, you’ve already done very well. The next steps require a long time, but mostly b/c you’re going to be transferring the files around. Actually, start this process before going to sleep. Boot back into your Macintosh HD clone you created (in my case “Useful Drive). Now it’s time to set up your SSD. Use the Mac OS X Installer you downloaded, and install Mac OS X onto the SSD. This has 2 reasons. One, it will create a recovery partition on your SSD. Two we will use Boot Camp Assistant to create our Boot Camp Partition on that SSD. With the installation complete, OS X will restart into the SSD. Follow the steps to set up OS X (this will all be deleted soon). Boot Camp is a bitch. She will not create a partition on a drive connected via USB (tried many times). Also I’m pretty sure she won’t let you choose which drive you want to create the partition on. Furthermore, if there is any discrepancy with the drive, even if it’s functioning fine, she will throw a hissy fit. Therefore I recommend the FIRST THING YOU DO once you’ve booted into your freshly installed OS X on your SSD is to launch Boot Camp Assistant, and create your boot camp partition. With that done, boot back into your OS X Clone Drive (Useful Drive for me), and start Paragon Boot Camp Backup by clicking on the menu bar icon and selecting “Open Application”. Now you’ll want to restore your Boot Camp backup you created earlier onto your newly created SSD boot camp partition. Again, Paragon Boot Camp backup doesn’t let you select a partition, instead you select the Drive and it automatically detects and restores your Windows backup onto the BOOT CAMP partition. As an aside: I tried to use WinClone to move my old BOOT CAMP from my HDD to my SSD. This just destroyed my HDD BOOT CAMP requiring me to run a repair from a Windows Install USB. I hate winclone. Do yourself a favor and stick with Paragon. They know what they’re doing. If all went well, you should be able to boot into your new BOOT CAMP on your SSD. This can be confusing, as you could end up with lots of drives in your boot camp menu with redundant names. It should be your second “Windows” option under boot camp. If in doubt boot into both, the faster one will be your SSD. If everything works, CREATE A RESTORE POINT IN WINDOWS. Funny things can happen when transferring drives, and having that restore point can save you a potentially having to re-transfer your windows partition. Shut down and boot back into your external USB Macintosh HD Backup/Clone. Now it’s finally time to create the Fusion Drive. To do this follow cpragman’s excellent guide on doing so here. NOTE: DO NOT DELETE YOUR BOOT CAMP PARTITION. His instructions say to input the following: Code: sudo diskutil cs create [AribtraryName] disk0 disk1s2 where disk0 is your SSD and disk1s2 is your Macintosh HD from your HDD. This allocates your whole SSD to the Fusion Drive, and leaves the BOOT CAMP and recovery partition from your HDD intact. We’re going for speed here, so what we instead want to do is: Code: sudo diskutil cs create [ArbitraryName] disk1 disk0s2 where disk1 is your HDD and disk0s2 is that temporary OS X installation we did. Creating the fusion drive is fast, and now comes the final stretch. Use SuperDuper! to restore your USB clone onto your newly created Fusion Drive. This took about 4 hours for me. Again, DO NOT TOUCH THE COMPUTER DURING THIS STEP. Let it sit its full hours. If you’re really curious push the fn key to wake the display and check the progress. Restart into your fusion drive, make sure everything is there and working. You’ll want to enable TRIM assuming the SSD you installed supports TRIM. To do so enter the following in terminal: Code: sudo trimforce enable . It will ask you if you’re sure, enter y for yes and it will restart. Here is a good writeup on the whole process. Now windows. Restart into windows and follow reddit's SSD optimization guide. If you installed a Samsung SSD, use their Magician’s Software to set up windows. DO NOT use “Over Provisioning”. This will mess with the Fusion Drive and Boot Camp installation and you’ll have to go back to step 16. Also, disable auto-brightness in windows as it makes everything dimmer. Congratulations, you’re done. You now have a one of a kind Mac set up in a way that Apple would never officially support. Your Fusion Drive is significantly better than what Apple offered, and in addition to that you’ve got an entire Windows Partition on your SSD. I would recommend doing some testing and any major system changes before deleting your backups you created in steps 1-5. Cost Breakdown: 1TB Samsung 850 Evo - $250 (I got a good deal) iFixit Adhesive kit - $20 with shipping Two cans of canned air - $5-$10 Thermal Paste/Grease - $5-$10 M.2 SATA to SATA adapter - $45 Overall: $350 Performance: It’s good. Really good. Everything is faster. Logging in, switching users, switching apps, starting apps, restarting the computer, spotlight is way faster. It makes El Capitan feel like Snow Leopard, and that’s high praise. That being said, it’s not jaw-droppingly fast. I think I’ll only fully be able to appreciate how good the SSD is by going back to a non-SSD setup and realizing how slow an HDD is. Here is the read/write performance for 5GB: On the second sweep the performance numbers start jumping around as the Fusion Drive starts to run out of space on the SSD and start reading and writing from the HDD, but the numbers still stay between 300 and 500 MB/s. I also expect these numbers to be slightly higher in Windows because it’s a pure SSD setup. In fact, I expect windows performance to make a greater jump than OS X performance, as (someone correct me if I’m wrong) the Windows partition would have been physically closer to the inside of the platter where rotational speeds (and therefore performance) are lower. One more note on performance. After almost exactly 3 years of ownership, accumulated dust had destroyed the fan’s ability to cool the computer. Playing BF4 (even with no GPU overclock) would cause the GPU to hit 95°C and thermal throttle. Now I can comfortably play BF4 while overclocking my GPU and sit comfortably between 75°C and 90°C. This gives an ENORMOUS graphical performance boost, and further highlights how stupid it is to use adhesive on an air-cooled system that will inevitably have to be cleaned. Quick Warning about the PSU: I got shocked a couple times during this repair. Even if the power is disconnected from the computer, the PSU’s capacitors will still be charged. These shocks weren’t bad, but they could be dangerous if you somehow get them to travel from your left your right hand. Rubber gloves are an option, but those solder points are sharp and could easily penetrate rubber gloves. iFixIt recommends not touching the solder points, but I found that laughably impossible to do. Instead make sure that you’ll only ever get shocked on one hand, ground that hand to the case while working with the PSU. Just lean your hand on the chin of the iMac. Keep your other hand in such a position that it won’t touch the solder leads. While powering on the system, keep your hands and fingers away from the electronics and make doubly sure you didn’t leave an extra screw laying around on the PSU or Logic Board! Conclusion: In 2012 the Fusion Drive option from apple cost $250 and added a 128GB SSD that wasn’t particularly fast. Newer fusion drive SSDs are PCIe based, and are blazingly fast, however apple has gotten greedy, and the 1TB fusion drive only comes with 24GB of flash storage. If you have a 2013 or newer iMac, buy an M.2 PCIe SSD (no adapter kit required), and follow the same procedure. The other great benefit to doing this procedure (rather than ordering a fusion drive from Apple) is that you can get your windows partition on the SSD. This is huge for me, as now I’ve got SSD speeds on both my Mac and Windows partitions, making the switch between Windows and Mac very fast. This upgrade was a massive PITA, and you need to be comfortable working with computer parts to do it. But really... there’s only one way to really get comfortable, and that’s to go out and do it! If I did this procedure again and followed the instructions as written, I’m pretty sure I could get it done in an afternoon, rather than 3 days. Considering that I plan on keeping this system for at least another 3 years, it was absolutely worth it!