"..Well, I saw very little to no increase in performance using ATA-66. Perhaps with a better hard drive, the results would be greatly improved. I don't see any reason to run out and get an ATA-66 controller at the current time unless you want to use up a PCI slot. Some motherboards, notably from Abit, are now shipping with ATA-66 support and Intel's 820 chipset will be coming out soon with built-in ATA-66. If you have a fast hard drive such as a 7200rpm or faster and have a free PCI slot, it may be worth getting the controller card, for everyone else, its probably not worth it.."