AMD's 760 chipset is pretty well-known these days, although it is hardly available. It supports AMD's Socket-A processors Athlon and Duron at processor bus clocks of 100 and 133 MHz. Additionally it provides DDR-SDRAM support. So far it is the fastest Athlon/Duron chipset to date.
While AMD designed the 761 north bridge as well as the 766 south bridge with ATA100-support and other goodies, you will find that most motherboards will team up the 761 north bridge with VIA's 686B south bridge instead, which is supposed to have less compatibility problems than AMD's 766.
ALi's MaGiK1 chipset comes with support of AMD's Socket-A processors for 100 as well as 133 MHz processor bus as well and it can be teamed up with PC66/100/133 SDRAM as well as PC1600 or PC2100 DDR-SDRAM.
The north bridge of this chipset is the M1647 chip . Below you find the block diagram.
The south bridge of MaGiK1 is the M1535+ chip , which, amongst other things, also offers ATA100 support.
VIA's Apollo KT133A is not exactly a newcomer. We know this chipset as Apollo KT133, found in the vast majority of SocketA-motherboards that are available. Now VIA was finally able to add support of the faster processor bus and called it Apollo KT133A. This chipset is the only in this test which does not support DDR-SDRAM.
It will be teamed up with VIA's VT82686B south bridge, which also features ATA100-support.