iMac 27' Late 2015 A1419 4K - SLOW Fusion hard drive replacement with new internal SSD, MUCH FASTER!

Disassembly of iMac 27" Late 2015 A1419 4K and replacement of damaged Fusion drive with a new 2.5 inch SSD.

► Parts:

► Get the NEW M1 Macs here (Amazon links):

► Timestamps:
00:00 Introduction
01:30 Attach SSD
01:56 Disk Utility
03:59 Tech Doctor adhesives
04:38 Open iMac screen
06:57 Hard drive removal
07:54 SSD install
09:57 Remove adhesives
11:47 Install Tech Doctor adhesives
14:13 Screen adhere
14:38 Conclusion

[scottadams]

Two suggestions for those that follow. First, CLEAN the internals! Use a vacuum with a soft brush attachment to remove as much dust from the components, the housing and fan as possible. You'll want to avoid any static electrical discharger so be VERY careful not to touch the logic board itself with the vacuum. Use canned air to blow out any residual dust. Your Mac will run cooler when it's clean. Second, remove the backing of the new screen adhesive first and attach it to the case. Then, after you've tested everything to make sure it's working normally, remove the screen-side adhesive's backing and carefully reattach the screen. Note that the screen is *very* fragile so put as little pressure on the it as possible, both when removing it and replacing it, and never, ever lean on it. A very nice and well-done video. 👍

[darrelhampton]

I followed these instructions on my slow 2015 iMac with fusion drive and it works perfectly. Thank you so much.

[michaels]

This was a very helpful vid. My MIL gave me her old iMac, same spec / year as yours and man was it slow. It was base spec (no fusion drive thankfully) and only 8GB of RAM. Upgraded to 32GB and an SSD and gave it a thorough cleaning. (So much cat hair and dust inside..eww). Here's my time results from doing this basic upgrade for those interested:

Start up: Old 1:12s > New 18s!
Opening Finder: Old 9.5s > Instant
Opening Photoshop: Old 50s > New 17s
Closing Photoshop: Old 9s > New 3s
Opening Illustrator: Old 1:03s > New 18s!
Opening Safari: Old 7.8s > New 2s

Unfortunately I messed up my screen alignment by 1mm when reattaching (only I notice it but now I can't NOT see it..) so when I re-do it I may try to put in an i7 processor in and add an NVMe SSD in addition. Thanks again!

[mariusbjonness]

Ah, the essence of YouTube, a to-the-point, Crystal clear, no bullshit explanatory video. Red Five, I'm going in!

[glasgood]

I purchased the 1TB crucial ssd and hdd adapter and adhesive strips from your link and followed your video and have successfully upgraded my late 2015 27” Retina iMac. Excellent guide, like how you supported the lcd screen against the wall. Very logical guide thank you 🙏

[andrefelixstudio]

Placing the box was a brilliant idea, nicely done!

[krisokumu]

Thanks so much for this. I bought two of these imacs for my business, didn't open them for a few months and then saw how terribly slow they run. Apple wouldn't accept return even though one had just been opened and the other was still boxed. I thought about changing the drive to SSD, glad to see this video and will get right to it. Thank you thank you!

[azy]

after racking my brain as to why it was running slow and running into a thread on the apple forums suggesting that big sur was too bloatted for the older imacs and reverting back to older os still didnt resolve the issue (hours wasted) This method worked like a charm. thank you so much for the step by step guide

[antoniiocostaa]

Very good video I managed to buy a MAC 27’ Just like the one in the video but it had HDD with the help of this video I managed to change the hard drive thanks it was hard work but the video helped a lot!

[DaniaBeech]

EXCELLENT!! I'll be doing this exact thing within the next couple days. Appreciate your calm, soothing presentation. I'm confident I can accomplish this easily now. Thank you!

[MISTERABZ]

Used this video to upgrade my 27 inch late 2015 iMac - I was being quoted between £80 to £150! - Thank you

[sabianfirst]

Great video; only one comment concerning the adhesive applications. I will be attempting this upgrade soon with an older iMac. I noticed that at first you removed the paper from adhesive strips both sides, then later you opted to leave the backing paper on top. I suggest to any viewers that you do use TWO small screwdrivers in the little holes (good idea), remove backing paper from BOTTOM ONLY, and align the adhesive strips according to the holes, then fasten to the case. LEAVE ALL BACKING PAPER on top of adhesive strips, connect cables, confirm boot, THEN remove backing paper from TOP OF adhesive strips to permanently adhere glass to case. Again, great video sir.

[ywwonglp]

No extra thermo sensor needed after changing to new SSD?

[boerboel]

Thank you Andrew, excellent video. But you left out some critical bits which seriously tripped me up. Most will want to upgrade the slow mechanical drive which is a member of the Fusion logical drive. Your video has the Fusion drive already split into 2 and you're not using the onboard PCIe SSD.

My scenario was this - identical Mac to this one in video, with 128Gb SSD and 1Tb mechanical drive, both presented as a SINGLE Fusion drive. I wanted to replace the 1TB mechanical drive with a 1TB SSD and keep the onboard SSD as well.
So I followed the steps, attached a 1Tb Samsung SSD via USB and used CCC to clone the Fusion drive to the Samsung. Removed the old mechanical drive, installed Samsung and system failed to boot (of course, Fusion drive now broken!). Booted with CMD + R to recovery, and ran "diskutil resetFusion" from within Terminal but it kicked up an error ("did not recognize verb resetFusion"). It was loading from the (old) recovery partition which is still MacOSX, Big Sur + Monterey is MacOS11 so command won't work. Here's how I sorted it:

Put the old drive back, system booted OK thankfully. This allowed me to download Monterey installer. Next I created a bootable USB stick (min 16Gb). Removed old disk, put in new, booted the Mac (with LAN/WiFi disconnected, NB!) into Recovery, this forced it to boot from USB containing new MacOS11.
Next I ran Terminal and again "diskutil resetFusion" which now worked! It wiped both Fusion member drives then created a new logical Fusion drive. It said "Note: you have two solid-state drives, this is nonstandard but OK". Once the ResetFusion command completed, exit Terminal then ran Install Monterey from the bootable USB which installed perfectly.

Critical to this is that you have a Time Machine backup to restore from, *clone will NOT work* unless you mount it as a 3rd disk to an already booting system then manually copy your data back. So cloning was a waste of time.
Also, a) do clean the inside while the screen is off and b) *never ever put the tape on immediately* - always test first, put the screen back on *without the tape* to make sure the system is booting & working OK.
Hope this helps someone.

[daktarioskarvannederhosen]

fusion drive was placed in pre 2013 imacs as well.

[albertbrooklyn]

Your videos are quite clear and useful, and after watching them I have upgraded my 2010 and 2012 iMacs' with internal SSDs'. The only thing to be aware of, if you were running Microsoft Office it will require that you buy another license. Though, given these upgraded models are "extra" machines I just use Apple and Numbers as needed.

[Booth]

I have a late 2012 with Catalina. The fusion drive only shows one drive on CCC to clone from. Are their steps missing from this video and if so what are they?

[KevinLonghurst-vx]

I’ve just completed this and the SSD on boot has come up with contact Apple support!!

[truthteller]

I think this is the FIRST video I've found that shows the hard drives AFTER the install. Looks like you confirmed what I guessed - the PCI flash storage just shows up as a separate drive that can be used. Is that correct? I bought a 460GB drive to put in place of the original 128GB.

[clivewuest]

Hi Andrew. Very informative video and very clearly explained, however I have a couple of queries if you can help. I too have a late 2015 27 imac with a fusion drive running Monteray and would like to upgrade the internal drive to SSD, however there seems to be confliting advise online as to whether you can do this because of the fusion element will only work with a mechanical hard drive. Yes doesn't make sense to me, but I don't want to open my machine up only to find it doesn't work. I noticed when you opened up your "about this Mac" / 'Storage" tab it showed a hard drive and a seperate flash storage drive, where as my only shows a 1TB Fusion Drive. Is there a reason for this Did Apple modify something or was it changed in Monteray. Your advice would be appreciated Thanks Clive