Samsung EVO 970 M.2 NVMe in iMac 2017

You computer does not have the required internal connection for the drive you’re inquiring about (EVO 970 M.2 NVMe).

Your next fastest method would be a EVO 970 M.2 NVMe in an external housing connected to a Thunderbolt 3 port on the back of your computer.

The next fastest would be connecting a SATA SSD drive internally and removing the HHD.

The external M.2 NVMe would also be an easier/ simpler method.

Maybe sort of.

First, did you buy a Fusion Drive or SSD equipped model, or the base-model with only the 5400rpm HDD? Models that shipped with the HDD only are often SATA-only and may lack an SSD blade slot as seen in the iFixit teardown.

Second, even if your iMac did have an Fusion/SSD, the SSD blade has a proprietary Apple connector. You would need either some sort of m2 to apple adapter or else find an SSD blade made for Macs (OWC is the only one I've heard of who makes those).

Third, the internal drive(s) aren't really considered user serviceable parts and require special equipment/parts to safely remove and reattach the screen. Using an external USB 3.1 or Thunderbolt 3 hard drive would be a lot simpler.

it does not look like it has m2 connectors at all iMac Intel 21.5" Retina 4K Display 2017 Teardown - iFixit

You have three options:

1. Replace that iMac with one that already has a faster blade SSD.
2. Replace the 2.5" 5400rpm SATA HDD with 2.5" SATA SSD.
3. Get and use a USB 3.0 or a USB-C/Thunderbolt 3 SSD.

Actually using a Thunderbolt 3 external SSD, would be faster than replacing the internal HDD with a 2.5" SATA SSD.

for a good example, see > https://eshop.macsales.com/shop/owc-envoy-pro-ex-thunderbolt-3

Do both. Replace the internal with an SATA SSD and use the external M.2 NVMe as the boot drive and that be the fastest combination you can do. Try to add as much memory as you can afford.

Now, with all that said, remember that this is a 5 year old computer and your money might be better spent on a new computer, if the budget permits.

I agree with joaogauer that an external SSD would be the better route to take. The #3 option would be the better option. Take a close look at these from OWC: WC Envoy Pro EX USB or USB-C.

Yes it is compatible.

[Link Edited by Moderator]

Oh, if the computer is going to be open anyway just stick to a SATA SSD and call it a day: the primary problem with the 5400rpm is the high latency and low IOPS: unless you are trying to do high-throughput stuff like 4K video editing 500+ MBps is more than enough.

Good luck with the RAM upgrade. Very ambitious.

How much memory do you currently have?

If you upgrade the drive internally you'll won't be able to easily move it over to a new Mac when you get one. An external SSD can be moved over as a backup clone or as an external storage drive.

Have you run any "cleaning", "optimizing", "speed-up" or anti-virus apps on your Mac?