Tom did an excellent indebt discussion of AGP 1x,2x and 4x with multiple tests. Outstanding read to understand AGP and the different configurations. Maybe a little bit old but as true today as when he composed the article. Highly recommended!!!!
<A HREF="http://www5.tomshardware.com/mainboard/00q1/000214/index.html" target="_new">http://www5.tomshardware.com/mainboard/00q1/000214/index.html</A>