What is with locked cores?

Are you referring to the 3-core AMD processors that are actually quad cores with a locked out core? I believe they are locked out because that core was unusable, so instead of trashing the entire CPU they simply locked out the core and sold it as a tri-core CPU.
 
it isn't if it is unusable, it is if it is below AMDs requirements.

If it produces slightly more heat, if it can't overclock quite as well, if it isn't quite as effecient as they wanted, if it has a maor manufacturing fault causeing problems, they will lock it off. The ones that you can unlock are the ones with minor problems, like producing a little too much heat or aren't quite as efficient or whatever, but only if you have a motherboard which has ACC, which is Advanced Core Control, you need that to be able to unlock the 4th core in the bios

On some though the 4th core doesn't work, it will cause system instability or just won't work at all, and if you get one of those you are unlucky because you can still unlock the 4th core, but obviously if it is hanging or BSODing or won't even post, it isn't usable so you are better sticking with a tri core CPU
 
in the same regard, can you re-lock an unstable core once you open, or is it kinda pandora's box?

Just wondering since i haven't played with acc yet. cheers
 
[-0MEGA-];1394477 said:
Are you referring to the 3-core AMD processors that are actually quad cores with a locked out core? I believe they are locked out because that core was unusable, so instead of trashing the entire CPU they simply locked out the core and sold it as a tri-core CPU.
Click to expand...

Kindof yes - it's called " Binning ",

In theory you are correct - but supply - and demand of consumers at a price point makes a difference too. CPU's are binned based on two things -
1) specs
2) Market demand

When chip makers create a CPU - only a certain percentage of the CPU wafers are up to spec. The rest are binned at the spec they fall under.

i.e. If out of a production batch of 100 cpu's, hypothetically, 50 % fall into spec at Phenom II 955, and 50 % fall into spec at 945. If 80 % of the demand is at the 945 price point - then some of the 955 spec'd cpu's will be clocked down at the manufacturer to a 945 and sold as a 945 - even though it's spec'd at a 955 off the production line. You can go into the BIOS and open up what was shut down by the mfr. That's why you can purchase 2 of the same chips - and the overclocking ability will ultimately vary.

You can apply the same concept for shuttiong down cores - and market forces. The Dual and triple core CPU's started at quad cores - and based on spec / and market demand - the chip mfr will shut down a core to meet the market supply for that product. When you purchase a dual core phenom II for example, you don't know if it's a dual core b/c the cores were unstable - OR - because there was more demand for that product than available product - so they shut down 2 cores to sell it as a dual core.

You can unlock a core in the BIOS - and shut it back down if unstable.

Here's an Article on Unlocking Phenom II core

Kindof simplistic - but hope that explains the concept.
 
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