32-bit I/O support Intel combined mode Older, unsupported HDIO_xxx ioctls SATA RAID Enabling, disabling and checking NCQ 32-bit I/O support Why doesn't libata support 32-bit I/O? Does libata support HDIO_SET_32BIT ioctl? First, some background. The vast majority of data transfer takes place via DMA. For newer SATA controllers, DMA is a requirement, even for the so-called PIO taskfile data transfer