Had problems with an OC with full Multi

[00stevo]

Like in the topic,i tried everything to get my board to boot even with a mild OC with my 12.5x multi but it just wasnt having it.However using the 12x multi @3.1 ghz its been running stable all day playing music/encoding files etc.Why is that? Why does reducing the multiplier produce better overclocks on some boards but hinders other boards? My P31 board could hit 3.8ghz with no problem with a much higher FSB despite it being a lesser board than the one i have now.