Why is ssd speed slow on mac mini?

Question

macOS

There is a Mac mini (Late 2012), it was delivered to the company to the HDD, SSD Crucial M4-CT128M4SSD2 (connected internally via SATA). It is installed with High Sierra 10.13.6 (17G65), APFS file system, trim enabled. Measuring the speed through the Blackmagic Speed ​​Test shows a maximum of 200Mb / s per record. For SSD, this is about nothing .. Therefore, I ask for advice on how to increase the speed.

Answer 1

No way. If you read the specifications of the CT128M4SSD2, you would notice that the maximum write speed is 175MB / s, and the read speed is 500MB / s.
You bought a cheap SSD and got the speed to match. Having dropped 1-2k, you could take Intel and get symmetrical read / write at 500 mb / s

Answer 2

200 is the same speed as SATA2

Answer 3

Here the question is in the volume of the SSD. If you look at the "marketing" specifications for the line (those that are published openly - on the website, etc.), you will most likely see something along the lines of "Write Speed: up to NNN MB/s". And this will be the speed of the largest SSD in the line.
However, if you open the datasheet, it will most likely list the speeds for each model/capacity, and that's where you will just see that the write speed drops with volume.
For your 128 GB drive, 200 MB/s is fine. To be faster, you need at least the next model with 256 GB on board.
Crucial / Micron M4, by the way, is a good workhorse. Yes, modern models will be faster, but judging by what the owners write on the forums, the M4 is highly likely to outperform them in terms of reliability (endurance), because. there inside the MLC and not the smallest technical process.