CONFIG_BLK_DEV_ALI15X3
I never tried this8, although I should've. Your IDE chipset will work without these options, but it'll probably be quite a lot faster if you do use them.
Thanks go to J. Waalboer mailto:jwaalboer@convolution.nl for finding this out and mentioning it. You'll most likely also want some hdparm-stuff to be done; according to Mr. Waalboer, you'll have optimal harddisk performance with
hdparm -X70 -k1 -c1 -d1 /dev/hda
however, if you do not trust me or him, and/or if you do not know what you are doing, don't play with hdparm too much. Please do remember that misuse of hdparm might fry your harddisk.