I just ran some WinSAT Latency tests on the same 2 SSDs (SSD-SATA & SSD-M.2) on the test rig. I found the tip on Toms HG. My results (posting whole test CP window) I suppose the 7+,8+ & 9+ are test scores? Spoiler
how can SSD with NVMe interface with such speed (2700 MB/s, 1400 MB/s) have boot time like this ? 28 seconds boot time is really slow for a ssd which is known to be very fast so there is clearly something wrong or there is some information that is missing. I know that SSD itself is not sufficiant to determine boot time speed and that you have to include in the test the whole pc configuration to get correct boot time but still, it does not explain this slow boot time. My laptop is not very fast, it has correct configuration (i5 5200U, 8 GB of ram) with SSD and the boot time is way faster that yours. i have SSD with sata port 6Gb/s that i bought few days ago (Micron SSD 1 Tera) whose speed is much lower compared to yours (R-500 MB/s, W-450 MB/s) and the boot time that i obtain is very fast (13 seconds). I measured the time between the moment when i push on the power button and the moment when the desktop appears and it is exactly 13 seconds. if i include the time where wifi or ethernet taskbar icon finishes loading, the timing reaches 20 seconds. Also, the laptop contains a lot of applications. So if we take a moment and think about that, all this proves that those speed that Manufacturors mention on their site have nothing to do with the reality or that speed depends on EFI bios and maniboard chipset as @Yen said previously which means that you are connecting this SSD NVMe on very old machine. So we need to know your pc configuration with Samsung 960 EVO M.2.
It may be that my BiOS shows the press delete for (post) setup utility for 4 seconds (how I like it) & it goes to the W10 dual boot menu before the lock screen. I do hit enter as soon as the OS choices boot menu pops-up. The 28 seconds to restart PC doesn't bother me.
oh ok, in case the machine has dual boot, it may take few more seconds for the boot time but still, 28 seconds remains a slow boot time for such type of SSD. So maybe having an old mainboard chipset could explain that boot time.
Could be a old chipset, my ASUS MB is about 1 year old I think. Plus I am clicking the Restart button & the restart takes a few seconds to get to the BiOS post screen. Mine it timed from clicking the restart (OS) button to the lock screen.
oh ok, i didn't unserstand it that way, so knowing that, it's totally normal even if i still believe that the boot time has to be a little bit faster with your SSD. ok, i stop now. i thought you measured the time from the moment when you pushed on the power button until the lock screen. if i time the same way you proceeded, it gives me the exact same timing (28 seconds). Edit : i timed again the same way (from restarting until login screen) and this time i reached 31 seconds