I've a HP p624w MB: M2N68-LA (Narra V 5) HP MB manual says it support up to AMD Phenom II X4. I've tried to install a Phenom II X4 940 Black, but unfortunately the the BIOS POST after pass the logo screen and devices listing display the following message: "ERROR, CPU Installed NOT supported"and the system shutdown in some seconds, I asked on HP online chat support and they have confirmed it MD support such CPU, the CPU is brand new, I've installed a new 650 Power Supply. The computers works OK with its original CPU a Sempron. Any idea ?