You said there was no control for core FID & VID in the bios.
The XPC must have Award bios then -> i.e it is either SA76G2 or SA76G2L model.

Either way you may want to try this: http://www.multiupload.nl/WLRLT8TDGD

It is a modded bios I made based on the most recent S10J bios.

CPU FID & VID controls added under "Advanced Bios Features" -> "CPU Feature".

This specific bios is PITA to modify as the standard tools cannot be used (will completely corrupt the bootblock).
Therefore even I checked there SHOULD NOT be any of such issues I cannot be completely sure since I cannot 'field test' it.

So try it on your own responsibility.