I replaced my development machine with 6 cores, 32 GB etc. I thought it would be simply inserting the existing HDDs and changing /etc/sysconfig/ifcfg-eth0 but, * in the UEFI "BIOS" USB2 and USB3 work. * in C5.11 USB2 works but USB3 does not. * in C6.5 (my install disk; OS be updated to C6.8) USB2 works but USB3 does not. On both C5 and C6 lsusb shows an entry for the plugged-in keyboard (USB2 socket) and for the wireless mouse (USB2 socket) but nothing else. Please does anyone have any ideas how to solve this baffling time-consuming problem ? Is is a UEFI (motherboard Asrock 970A-G/3.1) configuration matter or potentially the absence of a suitable USB3 driver for Centos ? Thank you. -- Regards, Paul. England, EU. England's place is in the European Union.