I'm trying to make BeagleBone Black <https://www.beagleboard.org/boards/beaglebone-black> into a programmable keyboard (and mouse, hopefully). It has one "USB device" port (mini-USB) and one more common "USB host" port (USB-A). It boots off microSD or eMMC. One frustration is slow speed of my SD cards. I have lots of them, 8-16GB and 5MB/s. Too slow to flash images, and too slow to run on it. So, I've been shopping around for a *fast* microSD card. What I don't understand is, - some U1 cards are faster than U3 cards. This means, I can't just search for "U3" cards. - Do you know why U3 cards are slower than U1 cards? - Any brand recommendation? - Canada Computer has lots of "Teamgroup". Are they good? They are new (to me). - Of course, can't go wrong with Samsung. But, not at $20 range. - no Kingston. All the dead cards were from Kingston.