what is the ideal bus spead to processor spead ratio

any one know?

I presume your talking FSB to Processor clock.

I doubt there is a fixed number. It will depend on a number of variables. A few I can think of:

processor architecture
memory bus width (bits)
L1, L2, L3 caches
clocks per cpu instruction
the program you're running

Generally speaking, both cpu clock and memory bus clock are both bottle necks and you want each as fast as possible, because either can slow down your system under certain circimstances.