XP-Mobile and locked PCI/AGP dividers

FBomba6

Junior Member
Jun 5, 2004
3
0
0
Recently I installed a new motherboard (Aopen AK77-600 Max based on VIA KT600) and the excellent XP-mobile 2400+ processor (AXMH2400FQQ4C). The unlocked multiplier and adjustable vCore are incredibly cool to play with, and CrystalCPUID PowerNow real-time throttling in Windows is really great!

Unfortunately I have some problems with FSB dividers.

Mobo BIOS does not recognize the CPU ("Unknown CPU type") and sets it at 6 x 100, which is common as far as I read in other posts. I can freely set FSB and multipliers, both within BIOS and Windows. My motherboard never changes PCI/AGP dividers that stay locked at 1/3 and 2/3!

In other words, if I try to set 133 Mhz FSB (factory specifications of XP-M 2400+) the PC does not boot because of PCI bus set at 44 Mhz.

On AK77-600 Max there's a "K7 host clock" jumper which has two possibile values: "auto detect" and "100 Mhz". None changes the board behaviour. My BIOS revision is R1.08 and I have two 512 Mb DDR400 RAM modules; the board uses a Cypress W312-02H clock generator.

Do you know of any hack or trick to solve this situation?

Thank you and bye from Italy
FB6
 

FBomba6

Junior Member
Jun 5, 2004
3
0
0
I think the board should have all the required ratios (it is meant for fast barton CPUs). They just don't kick in when required.

Any hack I could try?

Thnx
FB6
 

myocardia

Diamond Member
Jun 21, 2003
9,291
30
91
Nope, no hacks. Just get yourself an nForce2 chipset motherboard. It's the only chipset to own, if you have a mobile Barton. The Shuttle AN35N is only about $50 at newegg, and overclocks pretty well.
 

FBomba6

Junior Member
Jun 5, 2004
3
0
0
I'm beginning to think that AOpen BIOS determines the PCI/AGP ratio to use using detected FSB of the processor. In other words if it reads 100 FSB it will fix PCI to 1/3 regardless of what FSB I set (which is correctly applied). If I make the board believe that I have a 166 FSB CPU it will fix the ratio at 1/5.

Do you know of any pin modding trick or WPCREdit hack just to change detected FSB of XP-M processor?

Thank you
FB6