Q: I'm using Duron 1600MHz Applebred CPU on your K7 series motherboard. How come the CPU is only recognized as a Duron 1200MHz CPU?(11/14/2003) A: The FSB of Duron Applebred CPU (1400MHz to 1800MHz) is 266MHz. It is different from the former Duron CPU (FSB 200MHz). Please remember to adjust the FSB_SEL jumper to FSB 266MHz while using a Duron Applebred CPU.
https://www.asrock.com/support/K7Jumper.pdf