Continuing on the success of the original KT7 & KT7-RAID, ABIT swapped out the Northbridge chip with the new VIA KT133A giving the KT7s true 133 FSB support (Really 266 MHz because it's a DDR architecture) and hence the KT7A & KT7A-RAID were born. Physically there are no other major changes to the board. The two pictures below show you the VIA Northbridge & Southbridge chips. The Northbridge being the KT133A (nice and shiny!) with 133FSB support, and the Southbridge is the new 686B Southbridge supporting ATA/100. The RAID boards also include the HighPoint 370 chip to support an addition two ATA/100 channels (with the traditional RAID 0/1/0+1 abilities of course).
FULL STORY @ EXTREMEOVERCLOCKING (http://www.extremeoverclocking.com/reviews/motherboards/KT7A-RAID_1.html)