I was using an SBC with diskOnModule that support UDMA-2 .

The CPU was celeron 400MHz with 265M sdram and 2G DOM.

Tesing was made by writing 10MB data into a file using "write"
function, 1M bytes every time.

The average writing speed tested was about 900KB/s with vxWorks 6.4.
and 1.5MBPS with DOS 6.22.

About 3MB/s got when using and Hitachi 20G 2.5" harddisk that supports
ATA-6 (100MBPS) with
vxWorks 6.4.

I'm wondering whether these results are valid or not.
According to ataShow() 's ouput, UDMA-2 was supported by vxWorks.

Also, when booting from DOM, bootrom's ATA disk attaching process is
more than 30 seconds.
Any advice on speeding up boot process using DOM?