I think that it is doing fine.
HERE is some more data from Crucial.
Crucial said that they did their testing with "IO Meter", which is a free, open source program:
IO METER.
You may want to give it a try, if you can figure out how to use it. I tried it using default settings and got unbelievably low results on my Samsung SSD. It is a complex program with a lot of different settings.
Yogi