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Problems with unlocked x2 550

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February 19, 2010 7:17:05 AM

Hello.

I just got a phenom II x2 550 which i unlocked to x4 B50.
The motherboard used is Asrock K10N78D.

The CPU is stable in all applications ( cinebentch, performancetest, etc ).
But when I stress it with wPrime the OS locks after 2sec and I have to reset it.

I thought a core was damaged but running wPrime on any combination of 3 cores works, so as long as any 1 core is idle the test works.
5v and 12v were measured and they remain stable.
Extra CPU voltage doesn't seem to help.
The cpu MOSFETS get very hot during testing.
The motherboard is rated to handle processors with TDP of 125W.
Phenom II x2 550 is 80w.


What could be the problem / what do you advise?
Thanks.

More about : problems unlocked 550

February 19, 2010 8:02:14 AM

well, keep in mind that unlocking the extra cores raises the TDP considerably, id say 125w easily, more if you're overclocking AND unlocking. theres also the possibility that your particular chip didnt make the X4 cut due to a malfunction.

id put a high flow fan on those mosfets, play around with the voltage a bit, and see what that does. otherwise, you're probably out of luck. maybe try it on a different mobo?
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February 19, 2010 10:11:59 AM

The fact that your chip was sold as an X2 not and X4 means it has faults on the cores. It's never guaranteed that unlocking will work, so frankly if you're having problems with it then you're not one of the lucky ones.

Lock it back up and write it off as a good attempt.
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February 19, 2010 2:10:15 PM

Sounds like you've got yourself a triple core instead of a dual core.. That's still pretty good.

I have this same processor and I unlocked the 2 other cores as well. The only problem i get is that the temperatures on the other 2 cores read as 254c but it passed stress tests.
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February 19, 2010 2:24:57 PM

LePhuronn said:
The fact that your chip was sold as an X2 not and X4 means it has faults on the cores. It's never guaranteed that unlocking will work, so frankly if you're having problems with it then you're not one of the lucky ones.

Lock it back up and write it off as a good attempt.


His CPU is not faulty, if he can cinibench and it does not crash then he is good to go...

When a core is faulty normally it will crash regardless of what you are trying to do.


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February 19, 2010 2:25:54 PM

MichaelIvn said:
Hello.

I just got a phenom II x2 550 which i unlocked to x4 B50.
The motherboard used is Asrock K10N78D.

The CPU is stable in all applications ( cinebentch, performancetest, etc ).
But when I stress it with wPrime the OS locks after 2sec and I have to reset it.

I thought a core was damaged but running wPrime on any combination of 3 cores works, so as long as any 1 core is idle the test works.
5v and 12v were measured and they remain stable.
Extra CPU voltage doesn't seem to help.
The cpu MOSFETS get very hot during testing.
The motherboard is rated to handle processors with TDP of 125W.
Phenom II x2 550 is 80w.


What could be the problem / what do you advise?
Thanks.


Most of the time this happens when you do not key in the correct values in the Bios. Can you post what you have set in the Bios?

Can you also post all of your spec's?
February 20, 2010 12:48:36 PM

Ok after further testing it turns out that the problem is with prime95 large FFTs( stress RAM ).
I mounted heatsinks on the MOSFETS and mow they are < 40 - 50.

With 1.45v( 1.35 default ) I get:
x4 3.1Ghz Large FFTs - crash after 5 sec
x4 3.6Ghz Small FFTs - stable
x2 3.8Ghz Large FFTs - stable
x2 3.8Ghz Small FFTs - stable


Bios Options are default except NVCC( Nvidia ACC ) set to Per core ( all 2% ), Voltage & Multiplier adjusted via OCTuner( Asrock ).

System is:
Windows 7 x64
x2 550 BE
Titan Fenrir cooler
Asrock K10N78D
8GB 4x2GB Ram Dual Channel
450w chieftec pwer supply
8500gt

So what gives crashing with large FFTs x4 ?
Also what is the max voltage that you would recommend for 24x7 ?
Testing 1.55v System stayed < 55C.
Could I run 1.55 24/7?
February 20, 2010 12:52:55 PM

Cbrooks said:
I have this same processor and I unlocked the 2 other cores as well. The only problem i get is that the temperatures on the other 2 cores read as 254c but it passed stress tests.


After unlocking x2 550 to x4 core temps are not accurate, only CPU temp is valid. My cores show up @ 0C :) .
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February 20, 2010 8:38:27 PM

MichaelIvn said:
After unlocking x2 550 to x4 core temps are not accurate, only CPU temp is valid. My cores show up @ 0C :) .


Cause once you unlock you cannot see individual core temp, you just go by CPU temp. Everest and Speedfan give accurrate CPU temps.

Individual core-temp is useless, one core will always be warmer than the other/others.

Here is an example :

http://i683.photobucket.com/albums/vv199/OvrClkr/corete...



dont us OCtuner, use the Bios.... I have 2 Asrock boards that are more stable when everything is done in the Bios ;) 

Your CPU should not need more than 1.48v to operate at 3.8Ghz (x4)
!