Rumour: Phenom II X3 can have fourth core unlocked

Rumour: Phenom II X3 can have fourth core unlocked

Playwares reports that you can unlock the disabled fourth core on some Phenom II X3 710 CPUs.

Considering that AMD’s triple-core X3 CPUs are really quad-core CPUs with one of the cores disabled, it was only a matter of time before a tweak such as this came along. According to Playwares, you can enable the fourth core on a Phenom II X3 710 simply by selecting Auto in the Advanced Clock Calibration setting on a Biostar TA790GX 128M motherboard.

The site has posted some intriguing screenshots that show a test system’s startup screen before and after the BIOS change. It starts off detecting a Phenom II X3 710 that’s been overclocked to 3.12GHz, but after the BIOS setting it then detects the CPU as a 3.12GHz Phenom II X4 10, complete with four cores.

If this is genuine, then it doesn’t look like this is just the BIOS detecting the CPU wrongly either. The site has also run CPU-Z on the CPU before and after, which appears to show the same CPU with four cores after the BIOS change. Oddly, the CPU-Z screenshot detects the CPU as having an AM2+ socket rather than AM3, but this is how CPU-Z currently detects AM3 Phenom II X3 CPUs. The site also ran the CPU tests from 3DMark06 on the system, and the score increased from 3795 to 4776 with the extra core enabled. Meanwhile, to show that the system was stable, the site also ran Prime95 across all four CPUs.

Stability is going to be the issue here if anything, as there’s a good chance that some X3 CPUs will have their fourth core disabled because it was defective. This was always a potential benefit of AMD’s native quad-core design, as it allows AMD to simply disable one core of a quad-core CPU if one core is faulty, but still sell the CPU as a triple-core processor.

We’ve yet to try out this tweak for ourselves, and we're not entirely sure why adjusting the Advanced Clock Calibration setting would enable an extra core. Also, if this tweak is genuine then it’s still unlikely to work on every single Phenom II X3 710 processor out there. However, at a cost of £105.32 inc VAT for a Phenom II X3 710, you’d get a pretty good deal if you really could unlock the fourth core and get a quad-core CPU for just over £100.

If this tweak is genuine, would you be interested in picking up a cheap Phenom II X3 if you could unlock the fourth core? Let us know your thoughts in the forums.

Via VR-Zone


Discuss in the forums Reply
[USRF]Obiwan 24th February 2009, 10:39 Quote
I thought about this when I read the BT review of the x3 720. Maybe AMD just want to sell more processors by simply shutting down one core and sell more then a x4 but for lower price is also profit see. The fourth core does not even have to be faulty.
Psytek 24th February 2009, 13:02 Quote
I heard that this was only limited to a single batch of X3s, chances are, as time goes on, more and more X3s will be ones where the 4th core didn't pass testing.
Infection 25th February 2009, 04:11 Quote
Worked on my friends CPU, he purchased it 4 days ago.
Denis_iii 25th February 2009, 08:05 Quote
hope it works on the 720 and other M/B manufactuers cotton on and figure out how to enable this
I'd say as time goes on more and more quads will pass testing and x3's will be perfectly capable quads with one disabled core
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