The ECS K7S5A should have very good IDE performance!
By the way I have an ATA 133 Drive @ ATA 100 and a ATA 33 drive as well as a Pio mode 4 drive! I have had them all working together at various times! The ATA 133 drive always works at ATA 100 ( ATA 100 controlller ), the ATA 33 drive always works at ATA 33 and The Pio mode 4 drive always works at Pio mode 4!
By the way I have them all on an ECS k7S5A