If you are going from a BX to 815 and o/c, READ ME!!

[Professorbx]

Just thought Id pass on a little bit of recently gained experience. I used to have an ABIT bh6 with a cel566 o/c'd to 876, and just upgraded to an abit SA6R. My chip, which still hits 876 on my old motherboard, just hits about 760 on the board, at 1.75v. That is the same that it took for it to hit 876 on the bh6. I did a little testing with the wire voltage trick from hard ocp, and found it needs 1.85v to hit 850 on the 815. From talking to other upgraders, it seems that this is a common situation. A lot of people who upgrade are already feeding their cpu a little to much juice when overclocking to start with so they don't notice, but a lot of people will be dissappointed if they don't keep this in mind. I am not stating this as fact, as I have been wrong many times before, just an observation. Good luck to all, and hopefully any upgrades will go well.
Drew

 

[gfgray]

I think it has something to do with the onboard video. With onboard video enabled, we were unable to post our 566 @ 850 @ 1.75V until we got an AGP video card and disabled the onboard video. Still it would lock after a very short period of time in HalfLife.

I believe that the onboard video, even if it is disabled, is causing instability with the 815 chipset and is hindering overclockability.

I will probably test my 566 in a 440BX mobo.

 

[AdamK47]

The onboard video is automatically disabled when an AGP card is inserted.

Anyway, for overclocking a 66MHz bus CPU to 100MHz bus, the only real motherboard choice should be a BX.