Not great for a class 10

I'm pretty disappointed with the write for a class 10 card, it does not respect anything in its class. In reading and writing, the card is very slow to process files under 100 Mo. When his write access time, it is catastrophic.

Here are some explanations:

To 100MB
Sequential Playback: 20.76 Mb / sec
Sequential Write: 19.15 Mb / sec

To 512KB
Shuffle: 19.89 Mb / sec
Random Write: 1.50 Mb / sec

To 1GB
Sequential Playback: 20.76 Mb / sec
Sequential Write: 19.79 Mb / sec

Average read seek time 1.1 ms
Average access time write 280 ms !!!!!!

That is, if the card is recognized without any problems.