he means:" i'm using Asus Crosshair II NF780, AMD Athlon X2+ 7850 Black Edition, 800mhz Team Elite DDR2 Ram, 750Gb Hdd, 420w CM PSU (i assumed it's OEM or non-true power PSU), when i wanna OC my CPU but failed.... but when i placed the CPU in my old motherboard, i'm able to OC my CPU from 2.5ghz to 3.1Ghz. But, why i can't OC my CPU with Asus Crosshair II NF780"???

I think it's ur PSU's problem lor, izzit c/w your Cooler Master Centurion Casing?? Insufficient power supply gua?? u r using XFX 9800GTX, right?? try to change ur PSU to a true/ real power PSU and try again. should be OC'able gua. i assumed ur older motherboard dun have that XFX 9800GTX on it, right??

P5Q Deluxe user reporting!! anybody using this mobo with Q6600 or others cpu, please give comment on far u can OC using this board. tq! as for me, so far so good, just wanna fully test it's OC capability.