8GB Industrial MicroSD UHS-1 XU4 Linux

Manufacturer Part Number : Sandisk SDSDQAF3-008G-I
Interface : UHS-1 SDR104
More reliable MLC NAND memory inside

Sequential Write speed : 32.2MB/sec
Sequential Read speed : 75.7MB/sec
OS preinstalled
Ready to run out of the box

SD/eMMC PERFORMANCE

You can boot from a MicroSD card or an eMMC module. The MicroSD interface supports the higher performance UHS-1 mode as well.
File access of a 512MB file (read/write) on three different storage options shows distinct performance differences.
The eMMC 5.0 storage is ~7x faster than the MicroSD Class-10 card in read tests. The Industrial MicroSD UHS-1 card is ~4x faster than the MicroSD Class-10 card in read tests. The MicroSD UHS-1 card provides a great low-cost option for many applications!

Write command
sudo dd if=/dev/zero of=$(mount-path)/test oflag=direct bs=8M count=64

Read command 
sudo dd if=$(mount-path)/test of=/dev/null iflag=direct bs=8M