Here's on my home machine.  Just updated to the latest firmware. 

Crazy things for you to double check real quick "Sorry I skimmed and didn't read the full content of every reply"

To get the best performance out of your solid state especially boot performance I suggest the following items.

The basics:

• Update and configure your Bios for the optimal settings... IE AHCI on for your SATA/SAS drives, unless they are being utilized by a hardware raid controller.
• Update the Firmware on your drive(s)
• Perform a fresh install of your OS if it's the boot drive with a major change in technology... IE going from SATA legacy to SATA AHCI or from SATA to NVMe PCIe connectivity
• Install the latest drivers for your chipset and SATA/SAS/NVMe -- This is especially important to update your NVMe drivers if you're using a Samsung 950/960/970/etc with the driver pack from Samsung
• Eliminate everything prior to Windows Boot Manager or <Insert OS Here> so it doesn't wait on other boot options to time out before booting
• Ensure your system is setup to properly utilize the SSD with it's Garbage Collection tech and caching tweaks

For a typical 2.5" SATA/SAS connected drive

• Ensure it's plugged into Port 0 with AHCI Enabled and Hotswap disabled unless it's within a hotswap bay
• Perform a fresh install of your OS, preferably with the latest AHCI or raid controller drivers slipstreamed into your install media
• Perform any recomended tweaks suggested by your SSD manufacturer for the OS & version of OS that you're currently on
• Setup garbage collection "Not really an issue anymore after Windows 7"

For a Typical M.2 connected drive

For the most part it's the same as the above with two very vital BIOS configuration changes.  Set them to the specific config of your purchased Solid State Drive and don't rely on "Auto" for either.

• Number of assigned PCIe lanes allocated to it
• Operation mode of the SSD

I guess it's cryin time for me......

Can't understand why an M.2 card wouldn't be supported.

Crazy question, what's the part number of your SSD?  A quick google search brings up Enterprise class solid states which could be the issue as the consumer version of Samsung Magician may not have support for Enterprise class drives.

Not sure on part number. I bought it used, no packaging.

From Newegg specs.

Samsumg MZ1LV960HCJH 960GB PCI Express Gen3 x4 M.2 Enterprise SSD            

• 1.3DWPD; M.2 Form Factor
• 960GB NVMe PCIe Gen 3.0 x4
• Supplies 32 Gb/s of bandwidth
• Enterprise-grade power loss protection

Hard Drive SSD 960GB NVMe Protocol, PCI Express 3.0 x4, internal - 1.3DWPD, M.2 Form Factor, VNAND, Up to 1,000MB/s Sequential Read (128KB), Up to 870MB/s Sequential Write (128KB), Up to 240K IOPS Random Read IOPS (4KB), Up to 19K IOPS Random Write IOPS (4KB) - PM953 Series

Here is what Samsung Magician says.

My laptop benchmark

So, I'm having no SSD performance problem or any other problems that I can observe.  But the SanDisk SSD Dashboard says (a) that there's a newer firmware and ( that I should turn on a function called TRIM that releases space from deleted files.  I'm on Win10, and I've read that the TRIM functionality is really only of benefit on older version of Windows.  Are there good reasons to upgrade the firmware or turn on TRIM?

Samsung Magician automatically turned on Trim on my Win 10. As for the firmware all that I've seen is yes to upgrade, but I would do some research to find out what the upgrade consists of. It's kind of updating the bios of your motherboard. It upgrades the chip in your SSD. You know what they say "If it's not broke don't fix it."

If you want your system boot really fast you need UEFI bios onboard of both motherboard and videocard and Windows 8 or later.

It enables the fast boot function. With SSD it takes a just few seconds to boot from hitting the power button to a fully loaded desktop.

I got samsung 860 evo SSD in M2 form factor and my OS boots almost instantly.

I was shocked to freeze first time I saw this function working. I had to wait for about 2 minutes to boot and wait for all autorun programs to stop making lags to my desktop untill I cloned my system disk to an SSD and it boots at lightning speed even without clean OS reinstall.

TRIM is definitely something you want.  Without getting all techy, TRIM helps make things faster.  Here is what I got from a web page I think explains it.  
With TRIM, an SSD is no longer forced to save pages belonging to deleted files. ... And you don't need TRIM for garbage collection to work—but TRIM makes an SSD's garbage collection more efficient. That being said, if you're using a Mac, Apple doesn't support TRIM on third-party SSDs

Trim is something you need, no matter what the OS.

I have never seen a computer that did not experience a significant increase in speed.  I put one in a 7 year old laptop and it was so much faster, it felt like I had upgraded the entire thing.

The most likely reason you did not see an increase in performance is that your hard drive controller is not capable of utilizing the the increased speed available with an SSD.    This is often the case with pre-built brands.  The profit margin is so slim on computer stuff that the mfgrs build to the spec.  Example not using real life numbers.  If the HD the computer is built with can do 300mbs a second, in order to save money, they put a controller in that can only move data at 300mbs a second.  If you later go back and install a drive that is capable of 3000mbs  you don't see the increased speed because the controller is incapable of working that fast.  If your hardware can use the increased speed, I assure you, the speed increase you get moving from a mechanical hard drive to a solid state drive is very noticeable. But don't just use boot times, an SSD will improve the computer in most aspects

Ahh it is as I thought, the MZ1LV960HCJH is indeed an Enterprise class SSD which would make sense on it not working with the version of Samsung Magician that you have installed.

You could try uninstalling it and installing the Enterprise version from

https://www.samsung.com/semiconductor/minisite/ssd/download/tools/

I downloaded it, uninstalled the other, which would at least run.  This enterprise version won't install. I ran in admin mode, and in windows 8 compat. mode.  I get a flash of a cmd prompt window, then nothing.

Thanks for trying!

Another problem I am seeing.  In device manager, under storage controllers, MS has put it's own driver there. Surface NVMe controller. I have tried thrice to install the Samsung driver, but the MS driver remains.

https://www.sqlskills.com/blogs/glenn/beware-of-the-native-microsoft-nvme-driver/?unapproved=268404&moderation-hash=5935acf4a5863f4f51f6b5a22b34a598#comment-268404 

Just info.