need help with ATA100/IDE

[Ice9]

Now that I have my plan sorted out (sort of) I am looking at the hardware setup for my new, second hard drive.

I have an Asus A7V motherboard, which has a total of 4 IDE connectors:
1) Primary IDE
2) Secondary IDE
3) Primary Ultra ATA100 IDE
4) Secondary Ultra ATA100 IDE

My current setup is:
1) CD-ROM
2) CD-RW
3) Current HD
4) nothing

My question is: is there any performance bonus to have each device on its own IDE connector configured as a master? Or should I use master/slave configurations on the primary channels?

I am thinking of taking (3) and putting it on (4) and installing the new drive on (3).