I think those CPUs have fixed multipliers, so changing the setting has no effect.

Setting the BUS to 66MHz though, that will work. I have the same motherboard in my Pentium II rig, incidentally, a 450 - wonder how it compares to the P3 in the average application. It's a good motherboard in my experience, certainly a better choice than the Asus you've replaced with it. I have never attempted to alter the clock and I can't wire it up at this moment to see what it does, but it does default to 66MHz before I set it to the correct value, so as far as memory serves, this did yield ~300MHz, it will also slow down the video card (Or at least, the path data must take to get there will be slower) negating the fixed multiplier of the CPU a little.

I think you're right, I forgot that fixed multiplier... I'm happy this is a good board, I've never used this one before. Before manually setting correct values, the first boot used @66mhz FSB. I'll do some benchs, when I will be ready.

So: setting FSB @66mhz is not a good solution, talking about consumption (and life-span of the CPU maybe)?

Setting the FSB lower won't damage the CPU at all, in theory it may even increase the lifespan to some degree (There's a long scientific explanation about die quality and so on) so the FSB option is likely OK.

As far as I know, the voltage for the Slot 1 CPUs is set by pins on the CPU. It is more than likely that this is handled by some smaller, simpler logic which is independent of he BIOS. Or else the BIOS simply uses these pins and dose not allow user input.

The board defaults to 66 as a "Fail-safe" anyway, so I am fairly confident that setting the processor to this speed is safe.

Edit: Yes, Slot 1 has a set of pins labelled "Voltage ID" which set the correct voltage automatically. A quick Google of "Slot 1 Voltage ID Pins" should bring up some literature for this, the datasheets for most CPUs are available from Intel and also document this.