I have read too late, that the high-speed information is only valid for CF UDMA card. Thus, the description on the packaging. I have tested with 2 Samsung microSD cards Samsung 32GB EVO (48 MB / s) and Samsung 32GB Pro (90 MB / s). EVO = write 18MB / s Read 42MB / s Write PRO = 35 MB / s read 42 MB / s, since the Pro card from other already with 70 MB / s was tested here could probably the HAMA reader brakes. A Kingston USB3.0 Stick 64GB comes to my USB3.0 connection to 175 MB / s read and 95 MB / s when writing. So the USB port is not the brake.