Monday, March 9th 2009
Phenom II X4 800 Series Can Address Full 6 MB L3 Cache
While AMD played smart in diverting all its engineering resources in designing only one core: the Deneb / Shanghai, and then carving out umpteen SKUs out of them based on disabling cores, and/or setting L3 cache amounts, its implementation seems to be shoddy, to the least. Weeks ago, a Korean enthusiast found an easy way to unlock the factory-disabled fourth core on some Phenom II X3 (Heka) processors. A fresh report suggests that it is possible to enable the complete L3 cache on the Phenom II X4 800 series processors.
The series is AMD's line of Deneb-based 45 nm quad-core processors with 2 MB of L3 cache disabled, leaving 4 MB that can be addressed by the processor. An enthusiast found the Phenom II X4 810 processor to be spontaneously able to address 6 MB of L3 cache, when used on an ASRock AOD790GX /128M motherboard. The most likely cause of this could be "poorly-coded" motherboard BIOS that is able to see the Deneb core "as is". The motherboard was using BIOS version 1.40, that adds Phenom II support. The additional cache was found to have a positive impact on system performance. Beyond that, the enthusiast did not provide an explanation. After clearing the CMOS of the motherboard, it was able to correctly detect the processor with its intended specifications.
Source:
XTReview
The series is AMD's line of Deneb-based 45 nm quad-core processors with 2 MB of L3 cache disabled, leaving 4 MB that can be addressed by the processor. An enthusiast found the Phenom II X4 810 processor to be spontaneously able to address 6 MB of L3 cache, when used on an ASRock AOD790GX /128M motherboard. The most likely cause of this could be "poorly-coded" motherboard BIOS that is able to see the Deneb core "as is". The motherboard was using BIOS version 1.40, that adds Phenom II support. The additional cache was found to have a positive impact on system performance. Beyond that, the enthusiast did not provide an explanation. After clearing the CMOS of the motherboard, it was able to correctly detect the processor with its intended specifications.
15 Comments on Phenom II X4 800 Series Can Address Full 6 MB L3 Cache
Its just like the X800 pro VIVO -> XT and all the other gfx's that required minor mods.
Damn AMD, doing anything for sales eh lol
And yet again unlocking is done on crappy brand board :D.
This would mean that enabling core no. 4 would be enabling a core that had already been branded reject by the factory.
Is this wise? - I'd rather just buy a 4 core CPU - that has PASSED quality control - is there REALLY such a price difference?
But personally, I'd still rather pay the extra and not have to worry about stability - At the end of the day you are still unlocking a reject core.
I suppose its really down to where between cost & stability your requirements lie.
Also, once the bios's for these boards get updated this problem will go away away as these chips are all still on their first bios releases so they're far from optimized just yet. I'm sure a lot of people out there soiled their pants when they found these things though haha.
I however wouldn't try to do either of these on a daily basis because of the risk for instability that is bound to happen at some point.
Kei