I remember when those were very popular motherboards. I found a link at Overclockers.com that details a mod done to achieve control of both multiplier and CPU voltage settings, but it's pretty involved. https://web.archive.org/web/20051111050643/ht … /k7s5amodp1.htm

Thanks for that, and yeah, it seems to be rather involved for just a bit of overclocking. If I had a spare I'd consider giving it a shot, but I'm not great at soldering as it is, so I'll pass. I figured out it's AMIBCP 7.5 that you need to look at the BIOS, and indeed there just isn't any options in the BIOS to enable. Unfortunate.

My testing of the FSB progressed a bit further but seems to top out around FSB150 -- granted, right now I have a mobile 2200+ in there, and the issue could be power or VCore related (I'm using a rather 5v hungry Ti4200) rather than the chipset itself. I'll have to kick the multiplier down and then see if I can hit FSB166 to determine if it's really the chipset's fault or not. Even if it is, considering 735 is rated for 133/266 at max, it's not a bad showing at all.

I have an Amptron LM930 P4 motherboard - it's the P4 equivalent of the K7S5A. It also has an AMI BIOS, and I tried AMIBCP to see if I could enable FSB/memory ratio of 133/166, but I had no luck. It has a setting for 100/166, so the memory bandwidth was actually slightly better with a 100 MHz FSB P4 than a 133 MHz FSB P4 (though overall performance is still slightly better with a 2.8 GHz 133 FSB P4 than with the 100 MHz FSB 2.8 ). Frustrating, but one of the things that made bargain motherboards a bargain was a stripped down BIOS that didn't have the performance options that higher end ones did.