I have several MicroSD cards.. I've been checking them for performance.
I use them in a GoPro Hero 5 Black or in my Samsung S9 for photo and 4k video.
What cardreader was used?
At first I tried with my Kingston FCR-HS3 Card-Reader I usually use (for CF Cards) but I noticed about 10 MB/s slower transferrates each time.
So.. for testing I've been using now a USB3 MicroSD Adapter UHS-1
I've been using CrystalDiskMark.
I ran the benchmark 2 times, best result is shown.
You can click on the images to buy the cards from Amazon via RefLink.
Here are my test results:
SanDisk Extreme U3 V30 MicroSD XC 64 GB
SanDisk Extreme U3 V30 MicroSD XC 128 GB
SanDisk Ultra A1 10 MicroSD XC 64 GB