Less than a month after it was revealed that you could unlock the fourth core on some Phenom II X3 CPUs, budget motherboard manufacturer ASRock has jumped on the feature as a selling point for its motherboards. As well as claiming to be able to unlock the fourth core on some and Phenom II X3 CPUs, the company also claims that some of its motherboards can also unlock the full 6MB of Level 3 cache on some low-end Phenom II X4 CPUs.

The company says that both features can be enabled by selecting the AOD-ACC (AMD OverDrive - advanced clock calibration) feature in the BIOS, which was the same method used by Playwares to enable the fourth core on a Phenom II X3 710 using a Biostar TA790GX 128M motherboard.

ASRock says that the AOD-ACC feature unlocks 2MB of extra Level 3 cache on the Phenom II X4 805 and 810 CPUs, upping the L3 cache from 4MB to 6MB. Meanwhile, the motherboard manufacturer also says that the AOD-ACC feature will unlock the fourth core on Phenom II X3 710 and 720 Black Edition CPUs, which are basically quad-core CPUs with one of the cores disabled. The company has released CPU-Z screenshots with AOD-ACC enabled and disabled as evidence that the feature works.

However, although ASRock is marketing this as a feature of its motherboards, the company points out that your CPU won’t necessarily unlock with AOD-ACC enabled. “The success rate of this trick depends on the CPU version,” says ASRock, pointing that it’s tested a number of CPUs with mixed results. ASRock didn’t provide any figures for the success rate, but did say that a “certain percentage” of CPUs failed.

The company has listed seven motherboards that it’s successfully used to unlock the extra features of the aforementioned processors. This includes those based on AMD’s 790GX chipset, as well as some boards based on AMD’s 780G chipset with an SB710 Southbridge. ASRock is particularly proud of the latter combination on its A780GXH/128M motherboard, saying that the chipset’s support for AOD-ACC is an “Exclusive Worldwide First.”

Do you own a Phenom II CPU, and would you be interested in taking the gamble on an ASRock motherboard to see if you could unlock extra features? Let us know your thoughts in the forums.