Detection of UDMA
 

I want to install a new harddrive. the new drive has the capability to be hooked into the UDMA ports on my MB. Can Linux detect a HD installed this way? Will it care that 2 other drives are installed in the normal IDE slots on the MB? If Linux can interface with the UDMA ports how does it label the drives intalled there (i.e. /dev/hda, /dev/hdb....)?

there's generally no difference. you just want to use hdparm to ensure it's rutned on. it'll appear as a normal /dev/hdx device

http://www.linuxdoc.org/HOWTO/mini/Ultra-DMA.html