Unlocked 2800 wont post with lower multiplier ?

[Mr. Fancypants]

I have been trying to overclock my 2800 Barton CPU and have noticed that when I change the multiplier from the default 12.5 to 12.0, the computer will no longer POST. Subsequently, I am then forced to remove the cmos battery and clear it by moving the jumpers. I was hoping to do a 200 fsb with a lower mult. to make use of the ram. Any thoughts?

The cpu is around 2.3 Ghz (12.5 x 185) with 1.70 vcore @ 42 C. Memory timings are 11-2-2-2t. Prime95 has only been running for about 2 hours.

Few more questions:

Should I lock the PCI bus by setting the AGP at 66 mhz?

Also, what should my memory frequency be set at? Right now it is just on AUTO. I think 100% would be 1:1 ratio?




Heres my setup:

Asus A7N8X Deluxe rev 2.0 (Zalman cnps7000a)
2800 Barton (i wrote down the stepping but cant find it ATM)
1GB Kingston HyperX 3200 non-A (11-2-2-2t)
Radeon 9800 (Sapphire)
Seagate Barracuda 120gb

Thanks for your help!

 

[c627627]

Yes, switch from Auto to 100%.
AGP should be set to 66 yes.

Lower the multiplier way down, to find out how high you can raise the FSB first.

Vdimm voltage should be increased, increase Vcore voltage gradually and watch your temps.

 

[Mr. Fancypants]

Thanks for the reply. The only thing is that although I can select a lower multiplier, the computer wont boot with anything lower than 12.5 selected... hmmm