@linuxdev tank you for reacting on my post.
i got a Samsung portable SSD T3 it has a USB3.1 to USB-C. i also have a a Toshiba HDD whit USB3 and a Kingston 64GB flash USB whit USB3.0. it looks like the new stander for USB appliances is USB3. i have red a post ware indeed the solution was to force the USB port to stay USB2. speed is not the most imported thing we need at the moment. our prediction is that the processing of data is a bigger bottleneck than the R/W speed of the USB connection.
reading you comment linexdev, i’m starting to think that it is better to use the PCI lane or the on-board SATA connector. but to be honest we don’t have the time to change. the use of a USB connected drive is a little bit of a quick and dirty solution to our storage problem. but looking back it may had been better if we had used a SD or internal SSD. but that is further not imported.
what is the best way to go from here?
if i limit the USB port to USB2 is there a downside to it other than speed?
how do i limit the USB port?
is it still relevant/beneficial to look for does USB3 (tegra-xhci) binaries?