There's more than just going up in Vc with your system, you need to look at other several factors.
how he got his P5B-E to 540fsb.
Now, someone mentions this, the P5B-E limits your Vdimm to 2.1v but that's with the 1.01G rev whereas the 1.02G goes all the way up to 2.40v (See Link
I'm not sure how different is the P5B-E from my P5B Deluxe BIOS but see if you can pull this off:
I've let all the power saving features on (enabled) so that my CPU even overclocked will consume less energy and therefore the frequency will change from 2.0GHZ
to the full 3.0GHZ
when needed/full load.
I use a 2:3 ratio (which gives me a 1000mhz RAM Frequency), but you should run with a 1:1 ratio then the DRAM Frequency will read 664mhz or a 4:5 ratio which will be a 835mhz. And use a 2.1v or 2.20v for the 1:1 or 4:5 for Voltage RAM.