p4c800-e deluxe bios setting - enhanced or compatible IDE operate mode ?

I have just one PATA HD physically installed on primary Intel IDE master
connector. The user guide under Main manu give me an option for IDE
configuration: 1) enhanced and 2) compatible operate mode. The former is
for windows XP "native" OS, says the manual, and the manual recommends the
default setting "enhenced mode" should be set.

When I choose this "enhanced IDE operate mode" option and save and exit BIOS
rebooting my system the next time I go to BIOS settings I will discover that
my IDE device has now shifted position displaying that my HD is now
connected to "Third IDE master" which is actually not the case. Physically
it is still on primary Intel IDE connector and I am not using Promise RAID
IDE controller on my mobo.

The same logical BIOS display-error wil disappear when I choose "compatible
IDE operate mode" in BIOS settings.

My system is;
Windows XP pro
1 Maxtor 80 GB Ultra ATA 133 HD physicaly connected on INTEL pimary
connector as master.
1 ASUS CD-rom on primary as slave
1 ASUS DVD-rom on secondary as master

My questions a
- If I only have one PATA HD installed as stated above, should i choose
"compatible IDE mode" or "enhanced mode" ?

- Dos it make any difference in compatibility and performance if I choose
one or the other IDE mode setting ?

Thanks i advance

Michael Dancygier