Computer has Intel 865 chipset with ich5 southbridge.

There is one sata hard drive and one ide cdrom

In the bios I have the following options for SATA:

Auto mode: Auto
Combined mode: SATA and PATA are combined. Max of 2 ide drives per channel
Enhanced mode: enables both SATA and PATA. Max 6 ide devices
SATA only: SATA is operating in legacy mode.

No matter which I choose in WinXP SP1 shows in Device Manager as Intel 82801eb Ultra ATA storage controller. The hard drive also always shows as running in UDMA-5.

Since I don't intend to add any drives what would be the best choice for best performance?
thanks