Phenom II X3 - Enable and unlock the 4th core

It is not exactly a secret that Phenom Triple core processors in fact are a quad-core processor with one core disabled.  Now before we begin out little tail and you storm off to the stores, realize this .. one core being disabled is always for a reason. It might be a problematic core, slightly instable or just downright damaged. But if you are in luck, the 4th core works properly.  And now let me continue my little tail ..

A Korean user has discovered that it is rather easy to unlock the disabled core on Phenom II X3 processors, provided the motherboard supports the Advanced Clock Calibration (ACC) feature (790GX motherboards) and this trick seems to work with Triple core Phenom II X3 720 and Phenom II X3 710, codename Heka.

Only with the 904xxxx-stepping; this tweak seems to work, not with 0849xxxx. On an ASUS motherboard this little trick did not work, but it's confirmed to work on 790 motherboards from Biostar and Asrock.

In this example a Phenom II X3 710 was paired with a Biostar TA790GX 128M motherboard. The CPU was overclocked to 3.12 GHz, with a vCore setting of 1.37 V.

Here's what you could try out:

Set the appropriate BIOS setting for the Advanced Clock Calibration feature to "Auto", save settings and restart. The system will be able to deal with the disabled core, and off load some work to it. The processor with the "additional" core was tested to be Prime95 stable and was able to boost 3DMark06 CPU score by as much as 1,000 points. More screenshots here.

For those interested, the Phenom II X3 720 2.8GHz sells here for $149.99

AMD Athlon II, Phenom II and Sempron go EOL in Q4 2011 - 07/21/2011 09:27 AM
it's been rumored before, but it looks final. AMD's Athlon II, Phenom II and Sempron lineups will reach the end of their lives in Q4 2011. As reported earlier this year, AMD has very aggressive transi...

AMD to phase out Phenom II fast - 06/28/2011 10:46 AM
With all the new APU's and FX processors on the horizon AMD will

Phenom II X4 980 BE processor review - 05/03/2011 07:18 AM
AMDs current Deneb core over the past year and a half has been optimized and fine-tuned in many ways. As such, and honestly completely unneeded, AMD did decide to make their fastest Phenom II X4 proce...

AMD preps 3.70 GHz Phenom II X4 980 Black Edition Processor - 03/21/2011 11:26 AM
There are more and more signals on the web that AMD is prepping to release yet another faster clocked Phenom II X4 processor. This one would get a clock frequency of 3.70 GHz

Phenom II X4 975 Black Edition review - 01/04/2011 08:33 AM
Today two new products are launched by AMD, and here at Guru3D we'll review the fastest one. Let's have a peek first as to what AMD has got prepped for you with the right pricetag. It's that Phenom II...