I can now confirm that the problem I experienced booting my cloned Samsung 970 Evo plus NVMe SSD into Windows is now solved!
I was advised by Macrium to try booting into Windows in safe mode. They thought that loading Windows in safe mode with a minimum drivers, etc may enable Windows to boot far enough to find the new drive and load the NVMe drivers. I tried this and it worked! Once I was in Windows in safe mode I went to Device Manager and sure enough the Windows NVMe driver had been loaded and the drive was present.
I then logged out, shut down and restarted the laptop in standard mode and everything loaded as it should. I have now updated to the Samsung NVMe SSD driver and run some diagnostics and benchmarks. All is running as it should and much faster!
I would like to say a big thank you to all the forum users that took the time and effort to provide a response with help and suggestions to assist me with this problem.
Sometimes the simplest solutions are the ones that you don't think of!
Steve
TLDR: NVMe is faster. NVMe is PCIe used for storage.PCIe is always faster than SATA
I think the easiest way to understand this is to break it up into electrical/data standards and physical form factors.
Your 'traditional' 2.5 and 3.5 inch hard disk drives use physical and electrical sata standards for connectors
By Dsimic at English Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31262121
M.2 is a different family of connectors physically
By Sayeen - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=130292724
You'd notice the top and bottom pairs of connectors are keyed differently.
The top two are SATA M.2 and the bottom 2 are PCIe M.2
NVMe is the storage protocol that PCIe M.2 drives use - so all M.2 NVMe drives are PCIe. There's a few 'full sized' PCIe SSD around as well, but that's generally outside the scope of most folks who arn't running a rack at home for fun
Generally as of 2023, most M.2 drives are 2280. There's exceptions but you don't need to worry about them (the last 2 numbers indicate length in mm). Most PCs unless the manual says otherwise will accept either.
x1 Gen 4 and x1 gen 3
Its backward compatible. Gen 4 is faster than Gen 3 - its exactly the same as with different 'full sized' PCIe generations. I think Gen 5 uses a different physical connector. Basically the bigger number the better.
Practically if you want the fastest drive, match the generation of your slot with the drive (so if you have a PCIe gen 4, get a gen 4 compatible SSD, and if you have gen 3, get a gen 3 or 4 drive), and compare the ratings of the options you have - since implementations, things like controllers and actual chips differ.
Most desktop PCs will support Sata or NVMe/PCIe drives UNLESS stated explicitly otherwise
Best Answer
Yes, SATA and NVMe are completely different protocols. It just happens that the same M.2 (aka NGFF) form factor is used for both kinds of SSDs.
With M.2 slots built into motherboards, the same slot can be dynamically routed either to the SATA controller or to the PCI bus depending on what kind of SSD you install – but when using an external M.2-to-SATA adapter, it's obviously wired only to the SATA port.
If this SSD is just for data or programs (e.g. games), you can look for an adapter from M.2 to PCI Express slots, because every NVMe SSD is just a regular PCIe device. This would give you much better performance than SATA ever could.
However, motherboards without M.2 slots typically won't be able to boot from NVMe SSDs (their firmware will be missing the correct drivers).
So if this SSD is where your OS is installed, and if the motherboard doesn't have any M.2 slots built in, then you should get a SATA SSD for the OS instead – and use the 970 for programs/data. (It doesn't matter whether you use M.2 SATA through an adapter or 2.5" SATA directly, it's still the same SATA.)
I would guess that actual NVMe-to-SATA converters do exist, on the grounds of NVMe-to-USB converters existing, but it seems like a poor idea in general.