no way to know for sure without trying it on another board. took me a few days of tinkering in the bios to unlock my XII 555 to a quad. it was a very quirky and finnicky process, but its stable. however, ive built 2 other unlock-friendly machines that unlocked without issue..on mobos cheaper than mine no less.
does your board support higher wattage cpu's? 125-140w
have you bumped up vcore to around 1.4 before unlocking?
i had to bump voltage on nearly everything before it would boot and be stable, now im chillin at 3913mhz, 2087mhz ht link, 261mhz fsb, 1732mhz 9-9-9-24 ram speed.
definitely bump voltages on cpu and motherboard related items before unlocking. also note that it may not unlock, or you may only get 1 extra core out of it