scsi host1: uas scsi 1:0:0:0: Direct-Access JMicron Generic SD70 1104 PQ: 0 ANSI: 6 The device is recognised as UAS. From the perspective of the kernel we have a SCSI disk. I can only speculate that it needs a device specific SCSI command to enter the faster mode. From the UAS perspective selcting the right mode for a device should be handled within the device.