The A1 reads the SPD from the SRAM
and adjusts automatically.
Pretty aggressive
on the timings I've been told.
You can set FSB speed with a jumper
100 or 133 no overclocking here.
On the bright side you can select your clock multiplier
I overclocked the G3 to 800mhz..
I Wouldn't recommend you do that.
I'm chicken I set it back to 600 after trying it.
Warning Just make sure you are setting the clock jumpers not the voltage jumpers.
Kurt