Unlocking AMD Phenom II X2 550 Black Edition cores - what are the risks?

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I've got the above mentioned CPU and a GigaByte GA-MA790XT-UD4P motherboard, which should be capable of unlocking the extra two cores - if I'm lucky and they're not faulty. The Internet is full of instructions on how to do that.

What I don't have is spare money to buy new hardware if I brick something. What are the risks when attempting to do this? Is it completely safe, or can I be left with an expensive pile of junk? What should I keep in mind when doing so? Bigger cooler maybe (I'm running with the default box cooler)? Should I lower the frequencies too? I've never done any OC before.

Vilx-

Posted 2010-03-30T09:45:07.793

Reputation: 3 293

2In some cases the extra cores are disabled because they failed some test, in some cases they are disabled because of demand/pricing/politics. There is no way to know. – Nifle – 2010-03-30T10:53:07.047

Answers

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The risk of pure bricking are very low. You may, at worst, be forced to do a hard reset of the motherboard BIOS CMOS.

To verify your unlocked system, you should run Prime95 and other system verification tools.

Unlocking is not overclocking, but some parallels exist. OC generally causes higher CPU temperatures. Once unlocked, your processor has a higher TDP (peak thermal output). That means your stock cooler MAY or MAY NOT be adequate. It depends one what AMD shipped with your processor. If you can compare your cooler to someone who has a 125W (or even 140W) TDP AMD processor, you may be able to verify that you have enough cooling.

Upgrading to an aftermarket cooler has several benefits.

  • One, you can direct all output airflow towards a case output fan. The majority of stock coolers direct airflow in two directions. This usually causes hot air sent in one of those directions to be recirculated.
  • Two, you can reduce idle temperatures, which may increase the total lifetime of your processor.
  • Three, you can reduce peak temperatures, which may increase the immediate lifetime of your processor.
  • Four, it gives you a chance to use a high-tech thermal compound, which further lowers temperatures.
  • Five, they look cool.

Underclocking is usually a way to allow undervolting, which allows for lower temperatures and lower power consumption. Since unlocking a core is usually all about performance, I'm not sure what the point would be. Just get a bigger aftermarket cooler.

Since we are on the subject of heat and performance, please tell us about your total case cooling. Do you have as many cubic feet per minute (CFM) of air coming in through input fans as you do output fans? Is it a case that all air output goes through the power supply?

kmarsh

Posted 2010-03-30T09:45:07.793

Reputation: 4 632

Actually, I've got no case cooling. Currently I'm just running with the sides open, although that's going to change when my baby daughter learns to crawl (which should be pretty soon). Also the whole rig is pretty loud already, so I'm not very thrilled about the idea of more noisemaking fans (though I understand that it might become necessary if I manage to unlock the cores). Plus, I currently really don't have any extra money for computer upgrades. :P – Vilx- – 2010-03-30T20:51:32.517

Still, your answer is very good, confirming much of my own suspicions. Thank you for it! :) – Vilx- – 2010-03-30T20:52:30.297

2If you have no budget for new, quiet 120mm fans, loud fans can often be made silent (or at least not-so-loud) by cross wiring them to run at 7V instead of 5. Simply swap the wires at the Molex or fan header connector. Also watch little hands and power & reset buttons. Daddy gets all excited and funny when I push this button! – kmarsh – 2010-03-30T22:15:23.780

Hahaha! That last sentence made my day! True, so true! – Vilx- – 2010-03-31T09:10:40.933