Changing cores in a processor

Nashsafc

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Does disabling cores, give you more overclocking headroom for the cores remaining than if all four cores are enabled in a phenom ii processor? If there is a single core or dual core optimised game, could i actually increase the frequency of my phenom ii 720 processor to even more on stock voltage if i disable the third core. The phenom ii 720 is meant to overclock to 3.2ghz on stock voltage, so by disabling the third core i wonder if i would be able to push that frequency up just a bit more. I think the phenom ii (x2) 245 can overclock from 3ghz to 3.6ghz, that's a 600 mhz increment, the phenom ii 720 can overclock to 3.2ghz, that's a 400 mhz increment. Although i suppose the performance increase just isn't worth it. I'd have all the background applications turned off as well, as many as possible.
 
Disabling cores will most times allow some overclocking headroom, not so much because of voltage ,but more because there will be less heat to dissipate. I do not think it will help much, but you may have an option to disable some cores in the bios.

Is that a 720 BE right? If it is, it is multi unlocked anyway. Just give it a small bit of extra voltage, boost the multi and keep an eye on the temps.
 

Nashsafc

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yes it is. I am able to disable any ammount of cores or enable all four cores. Which is awsome, and it's soo easy. So far been doing overclocking tests. Familiar up to 3.3ghz on 3 cores and 3.1ghz on 4 cores at the moment with voltage increases noted down. I can guess the voltage requirement for 3.4ghz as there is a voltage pattern i seem to notice. So disabling more cores will not allow more stock voltage overclocking headroom? Actually i think with the cpu as a quad core enabled, i had to increase voltage more at 3.1ghz than i did as a 3 core cpu to 3.1ghz.
 

Nashsafc

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ok apart from that, is there meant to be a maxmum ddr3 ram frequency that the phenom ii 720 can support? They say that phenom ii 720 doesn't officialy support ddr3 1600mhz ram, but can it take it? I have ddr2 800mhz ram anyway, i'm just curious to know about this.
 

Most boards let you do it. In general it is either done with a memory multiplier or by overclocking the cpu core clock until the memory hits the desired mark. I have not bothered to push any AM3 systems that hard as they are find with 1333 imo.
 

loneninja

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Phenom II can usually do 1600+, but it is only officially rated for 1333. Your processor probably needs more voltage because the 4th core isn't as good as the others. Wouldn't surprise me if it limits your max overclock with it enabled.
 

isamuelson

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I know with my current overclock (x18 to boost it to 3.651 ghz), I can't get to 18.5 whether it's with 3 or 4 cores.

So I'm wondering if my 4th core is actually fine? When I unlock it and run at stock speeds (x14 for 2.8ghz), I don't have to increase voltage or anything, it just runs. With Prime95, I had no crashes. From what I understand, if one chip is bad in the batch, I heard they just mark them all bad? So that makes me wonder if my particular chip came out of a batch marked "bad" when in reality, if they had tested my actual chip it would have passed the test and made it as a true X4?

 

To keep up with demand, sometimes actual working X4's do have a core(s) disabled to make an X3 or X2. It is more then possible you have a full X4 with a core disabled.

To that end ATI used to disable Shader units from video cards to make lower end units. Same deal, sometimes defective units, other times working units. I had a X850 Pro and it unlocked to a X850XT without any ill effects(well it needed more cooling, but the XT had a better cooler).