The 8K7A uses the 686b for its southbridge and the AMD 761 for its northbridge. Read any articles about DDR and you will find that chipsets using the AMD 761 northbridge are the only DDR solutions that outperform KT133A chipsets and it is only by 10%. If you are looking to use your old PC133 RAM or something like that, the KT133A is probably the better choice, but if you are buying all new RAM anyway, the 8K7A is more attractive performance wise.