What is the point in locked CPU cores?

RealityClash

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May 1, 2010
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Hey just wondering why some CPUs are built with locked cores? Why not just have all cores unlocked when they are sold?
Is there any sort of performance difference between a CPU's original unlocked cores and unlocked cores that were originally locked if you get my meaning?

Thanks for any help :)
 
Phenom II X3/X2 and Athlon II X3 CPUs have their cores locked (L3 cache with the Athlon II sometimes), because the core is defective/unstable and will cause system instability. Otherwise, AMD locks some CPU cores when there is a higher demand for dual core or triple core CPUs.
 

enayet_redeemer

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Mar 20, 2009
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Generally, the demand of low priced Dual/Triple core CPUs is greater compared to Quad Cores. Thats why to meet the greater demand AMD disables one or two cores and release those as Triple/Dual core CPUs in the market. Also the CPUs which didn't pass stability and quality tests as Quad core (Core or Cache fault) are released as Dual/Triple (Mainly Core fault for Dual Core Phenom II, Cache for Quad core Athlon II and Core fault for Triple/Dual core Phenom II or Athlon II).

Also AMD follows a marketing strategy for the option of core unlock to lure the buyers on getting one or two cores unlocked and enjoy Triple/Quad core experience in a lower price point. This does not applicable always because there is no guarantee that someone can unlock core(s) of the processor he/she bought. Majority times cores/cache are disabled because of manufacturing faults.

Hope you get the answer to your queries.

Cheers.... :D
 

JofaMang

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Jun 14, 2009
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The core unlocking situation may have been an accidental PR goldmine for AMD. When it was first discovered about 1.5 years ago, AMD jumped all over getting ACC removed/altered to prevent core unlocking from becomming mainstream. Within a few months, though, as the knowledge grew and core unlocking possibility became a good enough reason to pick a budget AMD duo/tri core over a budget Intel, AMD grew silent and has let this all ride out. Their reputation has only been helped by this situation. Money can't buy the enthusiast word of mouth cred that unlocking has given AMD (or text-of-finger, if you like)

Since all the Phenom II (and athlon II tri/quads have their own wafter, just not the duos)chips are based on the same quad core wafer, and production quality only goes up over time, one would have to assume that the % of unlockable chips is increasing.

Realizing the value of the PR this situation has given AMD, they have neglected to institute the physical disabling or destruction of the locked cores.
 

randomkid

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Indeed. Bought an X3 720BE and an MSI 790FX just for unlocking... I am pleased having a personal experience about this and it's actually win-win with AMD otherwise getting more sales. I build one more PC with Athlon II X3 425 with the MSI 785GM-E51 and have been able to unlock it as well. Recommended the same build for someone else but haven't tried unlocking it so far...