Blog 008. Installing a Samsung Evo 960 NVME drive in your iMac

Blog 008. Installing a Samsung EVO NMVE drive in your iMac.

My main computer is a late 2014 27inch 5K iMac. I’ve had this since it was released and despite the temptation I am yet to upgrade as realistically it’s a very capable machine. Even 5 years later there is only a handful of Apple machines that perform faster on a multi core level. 

Although this started life as a relatively basic spec machine with an i5 processor, 8GB ram, 2GB GPU and a fusion drive through the years I’ve pretty much upgraded this to the top of line machine. It’s now featuring a i7 processor, 4GB GPU ram (see motherboard swap), 32GB ram and replaced the HDD with an SSD drive. 

One part that I never replaced however was the 128GB blade SSD drive. It was fast, and never really needed additional space since I had the second SSD drive in there along with a few external RAIDs’. Furthermore, traditionally you weren’t able to install aftermarket NVME SSD drives in an iMac for two reasons. One was bootable software support from the OS and two was the different pin configuration used by Apple. 

Recently the machine was feeling a bit slower than normal and after a bit of investigation I released that the Apple SSD was running considerably slower than expected.

I happened to have a Samsung 960 EVO NVME SSD drive sitting around, so I decided to find out whether I could replace the stock Apple SSD with this. To my surprise there were a few adaptors on the market to convert the Samsung pins to match the Apple motherboard PCIe input. I decided to go with this one personally for no other reason that it was available for a quicker delivery from Amazon UK. At this point note that the Samsung drive is not the only one that will work. In theory most NVME drives should work using this method however I recommend doing your own research before going ahead to ensure compatibility.

The first thing on the list was to clone my existing drive as I didn’t want to go through a fresh installation. As I didn’t have an external enclosure or adapter for the Samsung drive I had to find a work around. By using an enclosure you save yourself some time but the process isn’t much different if you have an external drive sitting around.

The steps are the following:

  1. Find an external drive you can either format or create a partition on.
  2. Using Disk Utility format the drive to Mac OS Extended (Journaled) with a GUID Partition MAP.
  3. Use Carbon Copy Cloner to create a clone of your current drive. I’ve used CCC for years now and never had any issues. The clone is as simple as choosing your current SSD as the Source in CCC and the freshly formatted drive in the destination source.
  4. Once the process if finished it will ask whether you want to create a bootable version of the drive which you will need to accept and wait a few more minutes.
  5. Restart your iMac and hold down the Option button on the keyboard to choose a boot drive.
  6. Boot your iMac from the USB drive you just created to make sure everything works. If this is an HDD or a flash drive be prepared for slower loading times.
  7. Once you make sure everything works shut down your iMac and get your tool kit out.

And now the hard part especially if you’ve never attempted to take your iMac apart before. I will not go through the steps as iFixit has an amazing guide ready for your already. Taking the display off is by far the most difficult part so take your time. Once you do you will face this:

A few screws later and you should have the logic board out. Turn it around remove the old SSD and slide the new one in.

Follow the reverse procedure now and within a few minutes you should have your iMac ready to boot. I’d recommend that you don’t seal your display just yet to make sure everything works.

Turn on your iMac holding down the Option key. The internal drive doesn’t have the OS installation yet so we need to clone our drive back. Load OS from your external drive and follow the same procedure by formatting the Samsung drive and then using CCC as above. Only this time clone the external drive to your internal drive. Once completed shut down your machine and get ready for the final step.

Before turning on the machine for the first time I’d recommend an NVRAM reset.

  1. Turn on your mac
  2. Press and hold the Command-Option-P-R keys immediately after you hear the startup sound
  3. Hold these keys until the computer restarts and you hear the startup sound for a second time
  4. Release the keys.

If everything went well your machine should now load from the new hard drive straight into the OS but look exactly as it was before you started the process with all your files in place.

The last thing I did was to check the performance of the new drive using the Blackmagic Speed test.

As you can see this is a huge improvement over the performance I was getting with the stock drive. While I cannot remember exactly I believe that the speeds of the stock drive when new where very similar to what I am getting with the Samsung drive now. I can’t quite figure out what was causing the slow down on the old drive so I’ll just put it down to old age.

One thing to note is that the Samsung drive is actually capable of much higher speeds, up to 3000MB/s however I believe this is limited due to the PCIe interface on the 2014 iMac. From my research these perform significantly better on the late 2015 iMacs and later.

This is not an upgrade I would recommend to everyone however if you are in a similar situation you now know that it’s certainly possible!