i have two mobo's that use the kt133a chipset with the 686b southbridge. one is the abit kt7a v1.3, the other is the msi k7t turbo-r limited edition. in both computers, running windows xp pro, i used hdtach 2.61 and get about 30% cpu utilization and about 66 MB/s burst. after tweaking the pci settings in the msi board i got it down to 20% cpu utilization and hitting 70 to 75 MB/s burst rate. i saw the same improvement using the built in promise ata100 controller. all drives are 7200 rpm with 8MB cache and are ata/100 and ata/133. i also installed george breese's pci latency patch version 0.20 build 21 just before i started tweaking the pci settings. i saw very little improvement. if anyone has any insight on this, please help me. thanks