There will be two versions of the KA7. The KA7 100 will come with UDMA ATA/100 built in via a Highpoint HPT370, while the plain old KA7 will use the VIA Southbridge's built-in UDMA ATA/66. The test system we used did not have the Highpoint HPT370 chip on-board, however, ABIT did have a beta version of their Hotrod 100 ATA/100 PCI card to install, which we used.
Yes, the system we used had an Athlon 900MHz in it! The core voltage was set at 1.8v. IO was at 3.3 V. The FSB was at the normal 200MHz setting.
