32GB Ultra Micro SD not giving class 10 speed


I have purchased Sandisk Ultra 32 GB Micro SD UHS-I Card.

After 3-4 months it failed and I got a replacement card.

As per my tests I’m not getting class 10 compliant write speeds.

As per the description and the specifications written on the packaging it says that it is class 10 compliant , so is it really class 10 compliant?

If it is so then why it’s giving me speeds around 7-8 Mbps with respect to what I should get on the basis of the specifications.

 The 2-3Mbps difference really matters to me as I’ve brought this card just for speed and data transfer and it’s not matching what I expected from it.

My test device platform:

PC - 7-8 Mbps write speed

Samsung galaxy S3- 7-8 Mbps write speed

PC USB 3- 7-8 Mbps write speed