Unlocking AMD CPU Cores Safe Say Mobo Makers
While browsing through motherboards at Computex, several manufacturers were quick to tell us some details about the recently released dual-core Phenom II CPUs from AMD.
Two motherboard makers told us at the show that AMD's new processors are safe when unlocking disabled cores. In fact, one motherboard maker even told us that when you unlock the disabled cores, they run at slower frequencies than the normal cores.
This is of course all incorrect, and it is indeed not a safe guarantee when you unlock the disabled cores. The reason for this is that the disabled cores are turned off for a reason: they failed factory tests. Cores can fail for any number of reasons, including defects in the silicon, problems running at full frequency, or a bug introduced during manufacturing.
Both AMD and Intel disable CPU cores for this very reason.
When you unlock the disabled cores, they will run at full processor frequency, since you cannot run each core at different speeds. While you may see initial gains and benefits from turning a dual-core CPU into a quad-core CPU, you may introduce instability into your system. Things may corrupt, calculate incorrectly or even crash.
Despite what we were told, we still recommend that if you're going to unlock disabled cores, do so with caution in mind--there is always a risk that something will go wrong.
very interesting, thanks.
there are in some tri and dual core chips since they are often rebinned quads that failed QA testing. tho i think AMD doesn't put out many if any dual cores that were once quads since they use a real dual core/single die unlike wot intel did with core2.
AMD disables cores and sells them in a lower segment because it's more financially sound than just tossing them out.
I've never heard of Intel disabling cores, but I wouldn't be surprised if some of the dual-core CPUs were like that.
Intel and AMD still has to straiten things out on thoses quads
If they disabled both cores from one dual core side I guess that would work, but would be horribly inefficient, unless they only used this for one specific model and made the rest regular dual cores.
How do you think the cores were turned off in the first place? They were fused. One can never perfectly undo something with software (i.e. BIOS settings) that was PHYSICALLY altered to start with.
Just buy a quad-core if you want a quad-core. Save yourself the headache, risk, and uncertainty.
Also, cores are not turned off simply for binning purposes or because they "failed factory tests." This is completely untrue. Do some dual- and triple-core processors actually have faulty cores that are turned off? Yes. Do all of them? No. Especially as wafer manufacturing processes improve, you end up with a lot of good dies all with 4 cores perfect.
AMD intentionally disables even good cores simply so they can have product lines in a different market segment. Why build an entirely new architecture of 45nm chips for dual cores when you can just fuse 2 perfectly good cores, slap it in a box, and put a $75 price tag on it? Some people just do not need a Phenom II 955 but would love a Phenom II 550.
Tom's needs to do their homework before committing pen to paper.
It was supposed to have closed a long time ago. That isn't stopping motherboard vendors from dragging their feet on BIOS updates, and end-users aren't forced to flash their BIOSes, essentially disabling the capability. So long as AMD doesn't disable this at a processor-level, people will continue trying it and, in some cases, succeeding.
A true parental lock...
A true parental lock...
On all Phenom II processors you can adjust the frequency of each core individually using AMD overdrive. This is well known to anyone who overclocks AMD cpus.
And it is safe to unlock extra cores in the context that it 'will not damage your hardware'. Instability is always an issue when running outside manufactures specs. So the only valid point this article has is.. 'warning unlocked cores might not be 100% stable'.. Thanks, but we already knew that.
A bunch of single-core Core 2-based Celerons are dual-core chips with one core turned off. Core Solos were Core Duos with a turned-off die. The Xeon E5502 is a dual-core made from a quad-core die.
These companies also disable perfectly good chips to meet demand of lower priced parts.
If you make 1000 processors and 900 of them bin at the top speed grade, what do you do, sell 1 processor to the person who can afford it and the 100 cheap ones to entry level buyers. Or do you stamp a lower speed grade on the other 899 top bins and sell them to mid range buyers at a lower price and a hihdered speed rating.
It makes perfect business sense to sell perfectly good chips with parts disabled to meet lower price segments.
Thus NOT ALL of them will have bad parts, some of them will be 100% functional. And also NOT ALL of them will be perfectly good parts, some will have bad parts disabled.
So as with any overclocking of parts, you run them out of spec at your own risk. A lot of the time you will be perfectly fine, sometimes you wont.