5% vcore increase? Wth?

This pos Biostar G31M motherboard has a vcore adjustment in percentages lol!
First choice is 5%.I will need a bump to get my E5400 to and past 3.2ghz.Currently up to 3ghz from 2.7ghz with stock volts and good temps.I'm scared to add 5% volts at one time though.I already have the pci-e set manually to 100mhz.
What do you guys think?Stick with my current stable clock of 3ghz?Or give it 5% and go for 3.2 and more?I already know windows crashes at 3.2 with stock volts so...
I'm also using the stock Intel air cooler for now.

A 5% increase is only .05-.06 of a volt depending on the VID, so w/ say a VID of 1.2 that comes out to only 1.26V, which isn't even a tenth of a volt.

Ya know,thanks for brushing up my math redduck900 lol!I'll give it a shot and watch the temps with the stock cooler.
Thanks.