From the Register...
........"A serious design defect in Via chipsets results in boards based on them substantially underforming motherboards with chipsets from Intel, SiS and ALi, a series of tests conducted by tecChannel.de has shown. The problem affects boards using both Intel and AMD chips, and the hit to hard disk performance is sufficient for tecChannel to say: "we can currently not recommend VIA chipsets for professional users who demand high performance from their hard drives and think about setting up RAID configurations."
.......read the article @ http://www.theregister.co.uk/content/54/23502.html
This is the main reason I'm considering the Iwill XP333R (ALi chipset) over any of the new VIA's coming out with ata133 support. Make sure you read up on any mobo you are considering. Shuttle has decided not to use the VT8233A Southbridge but rather went back to the VT8233 on their soon to be released AK35GTR. The good news there is that the RAID version will be equipped with a Hpt372 ata133 RAID controller o/b and you'll be able to run a single HDD with ata133 capabilities in a non-RAID fashion with that.