Abit AN7 doesn't want to overcklock

[Munky]

I have a mobile barton 2500 and 2*512 mb OCZ vx gold 4000 ram. Currently running on my Abit AN7 motherboard, and although the processor overclocks well to 2.5ghz, I can't get the fsb to run stable past 204 mhz, which is a lousy 4 mhz overcklock. I heard these boards can do 240 mhz fsb, so what can be the problem?

I tried increasing the NB voltage, loosening ram timings, lowering fsb/ram ratio, lowering the multiplier, even replaced the NB heatsink with a bigger one, and added heatsinks to the south bridge and voltage regulators. Also, tried several bios versions, including modded ones. Even tried taking out 1 stick of ram, still not good. My PSU is a 420watt OCZ powerstream, so it shouldn't pose a problem.

If anyone has this board, or the similar nf7-s, let me know what you guys did to overclock yours. Did you do any kind of volt mods?

Voltage: 1.78 cpu, 1.75 nb, 3.2 ram, 1.65 agp
Temps (load): 54 cpu, 34 nb.

 

[ChineseDemocracyGNR]

Do you have other memory you could try?

 

[Munky]

Actually I do have a stick of ddr333, so I'll try that when I get home.

Edit: BTW, the way I test if it's stable is to first run memtest after changing the bios options, and it fails memtest at anything above 204 fsb, so it might have issues with the ram I'm using.

 

[Munky]

OK, I tried the other ram, and it seems to be stable at 215 fsb. Still nowhere near the overclock I was shooting for, and running ddr333 is really not an option. Also, I'm thinking maybe heat is the issue, because using OCZ VX ram at only 2.6v it passed memtest the first time around at 210fsb, but the second round it got errors. Anyway, the OCZ VX performs better than any other ram at the same speed, so I should just be happy with what I get out of it. In Everest I'm getting 78ns latency, which supposedly beats even some A64 systems, and all the AXP systems.