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Hi I want to replace the HD in my iMac 27" 5k systems Fusion Drive with a SSD. Can I run this iMac with a 24 G flash drive on motherboard (apparently this flash drive is not yet upgradeable?) and this new SSD (in the place of the HD) Essentially I would have 2 SSD drives (one big and one small) How do I set it up after the install?
Frankly, I would not upgrade this system as it has a faster Thunderbolt external port than what the internal HD SATA III port offers. Lets look at the numbers: SATA III - 6.0 Gb/sThunderbolt 1 - 10 Gb/sThunderbolt 2 - 20 Gb/s So depending on which exact model you have you might have a TB2 interface which is much faster! Now lets look at the PCIe interface the blade SSD is currently using PCIe 2 Lane (AHCI) - 10 Gb/sPCIe 4 Lane (NVMe) - 32 Gb/s So if you wanted a faster system using an internal drive I would invest the effort replacing the blade SSD with a much bigger SSD unit. Apple offers a 1 TB bade SSD but it will be expensive! If you have the older PCIe 2 Lane (AHCI) model there are some 3rd party options coming out this Spring so I would wait. So far there is no PCIe 4 Lane (NVMe) option other than Apple. In either case Apple uses a custom SSD so you can’t use the now more common M.2 blade SSD’s. If you really want to replace your current HD you have some issues as you will need a special cable harness to replace the HD’s thermal sensor. This is what you’ll need: OWC In-line Digital Thermal Sensor for Hard Drive Upgrade for 27" iMacs 2012 and Later and you’ll need this frame: OWC 2.5" to 3.5" Drive Adapter Bracket to hold your SSD. Opening up the ‘Thin Series’ iMac’s is a big under taking! Make sure you follow the IFIXIT guides to the letter as you can damage the display assembly quite easily if you don’t use the correct tools and technique.
There’s a 1TB Western Digital Black and a 24 GB Apple SSD in your computer. You can essentially replace both of them. The hard drive is the usual 3.5" SATA slot. While the Apple SSD slot uses a M.2 adapter. So something like a 850 Pro will do. I would only do this if I was a very experienced computer specialist. Disassembly the Apple Mac 5K is a very risky process and can result in potentially damaging cables or shocking yourself. iFixit Disassembly guides here: Hard Drive: iMac Intel 27" Retina 5K Display Hard Drive Replacement Solid State Drive: iMac Intel 27" Retina 5K Display Blade SSD Replacement
Hey Dan, how do you know what PCIe Lane model you have? I have the 5K Late 2015 27" iMac 3.2 i5 with the 24GB Fusion Drive. I bought this about 10 months ago and thought I was getting 128GB Otherwise, I would got the 2TB one. I think I’m willing to pay for it within reason, but how do I purchase one? Thanks. I been reading your posts and the info you have is very informative.
hello guys I’m at the exact same problem . Just one question: Can I remove the SSD blade and the SATA HDD and connect a 1 TB SSD there? Is it possible? Many thanks in advance
Although the suggestion of using an external thunderbolt connected SSD is a good idea, I would like to point out that on the iMac, and possibly all thunderbolt connectors are a poor design. The cable/connector interface is too fragile and loose in my opinion. My external thunderbolt connected drives are constantly disconnecting whenever I tilt the display or move cables near the drive ends. And yes, I have tried multiple thunderbolt cables. So if you want a reliable boot drive, go with an internal SSD.
Re the original posters question, Thunderbolt and replacing the blade SSD in the Mac aside, I’m not sure I saw anything definitive about how to best use the fusion drive if the decision is to replace the HHD with an SSD. Can it still be a fusion drive? Will the mac know to keep the system stuff for booting on the PCI based SSD? What would happen if I didn’t “break” the fusion before pulling the HHD and simply installed the SSD in the SATA spot. Would it automatically try to create a new Fusion setup? (obviously a backup of the original system would be on hand).
If you want to increase the speed of your iMac, just replace internal HD with SSD, you don’t need to configure or to replace blade (PCIe SSD). You need to install macOS on the internal SSD (the new one). Fusion will not be configured automatically, there is only one way to configure it again and that you can do from Terminal (Internet Recovery Terminal), just type diskutil resetFusion and confirm with “Yes”. Before this procedure, be sure that you have backup of all of your data, because all data will be erased after resetFusion.
