MicroSD card performance

Question

I am having problems with microSD performance, I did these test using HD Tune and a Kingston FCR-HS3 (https://www.kingston.com/en/flash/readers/fcr-hs3) on a USB3 port.

I am a bit confused, especially with the 256 GB is that the expected performance of these?

Thanks.

Answer 1

Was the card as cheap as it performs? I would never buy a no-name card if I don't know the exact specs beforehand. You will always run into some kind of trouble.

According to the Speed Class rating (the 1 inside the U) the card should have a write speed of at least 10MB/s and reads should be much higher. But real world values differ a lot!

Example:

My fastest card I own is a SanDisk Ultra 64GB Class 10 (which strangely is the same as Class 1) with a sequential write speed of 65.379 MB/s (read 74.370 MB/s), tested with CrystalDiskMark. I could not believe it and tested it several times. Another SanDisk Ultra 64 GB with both A1 and C10 marking "only" makes 18.793 MB/s (76.011 MB/s read).