According to the news post over at VR-Zone, motherboard makers have also confirmed the Phenom II X3 unlock, and apparently some others like Gigabyte are saying the same story.

Guys from VR-Zone apparently managed to get a screenshot from DFI that shows an unlocked Phenom II X3 running four cores on DFI's LP DX 790FXB-M2RS motherboard, and according to them similar success has been reported from Biostar, Gigabyte and others as well.

According to some other information on the net, this can be done on 0904 batches of Phenom II X3 CPU's and still we must note that there is no guarantee that is will be stable as some of those CPUs are indeed a true triple-core due to the some sort of defect on the fourth core. The other theory is that the forth core is simply disabled and that all four cores works just fine.

You can find the noted screenshot here.