Hello,

I intend to run cdrecord concurrently on multiple cdwriters.
Dmesg seems to report that the drive has DMA mode 2 and Ultra-DMA
mode 2 (Ultra/33).

cd1 at atapibus1 drive 0: <PLEXTOR CD-R   PX-W4012A, 563001, 1.02> type 5 cdrom removable
cd1: 32-bit data port
cd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2 (Ultra/33)
cd1(pciide1:0:0): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data transfers)

Nevertheless when burning by cdrecord (1.10) on a single drive the
CPU is already loaded to much. It seems to me that DMA is turned off.

How can one control the data transfer mode of Atapi drives?

-Hanspeter