amlett did a similar comparison already: http://www.xtremesystems.org/forums/...MX4-PK1-LQP-IX

I definitely wasn't stable with 47x @ 1.325 vcore and I don't see the point in going further since I wouldn't use a vcore any higher than that for 24/7 anyway. So I stopped it back down to 46x and I'm running @ 1.275 vcore right now. 200mhz improvement by replacing stock TIM with AS5. Not too shabby.