In my system, I have an ASUS P4533 motherboard and UltraDMA/133 hard drive. 
Although the motherboard's specs say that it supports UltraDMA/133, I noticed 
that, under NetBSD, the disk is accessed using UltraDMA/33.

Are there any plans of supporting UltraDMA/133 on this motherboard ?

The IDE controller is a Silicon Integrated System 5597/5598 and, according to 
pciide.c, the driver is set to use UltraDMA/100 on SiS 735 and UltraDMA/33 on 
other chipsets. Would it be possible to just set sc->sc_wdcdev.UDMA_cap to 5 
(or 6...) in order to get a quick fix supporting UltraDMA/133 on the ASUS ?