Unlocking The 4th Core: Phenom X3 720BE

[pswfps]

Hi,

I recently discovered that my mobo is able to unlock the 4th core on my X3 720BE. It all "seems" ok but I'm a little worried about whether this is a good idea TBH.

The machine POSTed fine, I saw "Phenom II X4 20" and Vista 64 booted no problem. I saw all four cores in the windows task manager. It ran Prime95 and AMD overdrive stress tests each for hours on end (12 to be exact) without any issues. With a Scythe Ninja II cooler, it didn't seem to run significantly hotter than the tri-core either. But I'm still worried.

About a week after unlocking, it was an automated Vista backup run which was the first to complain. Apparently the file system had become corrupt on my main system drive and it couldn't be backed up any longer. Well that's never happened before...

So I schedule a chkdsk to run on next boot. Sure enough it found loads of issues but was unable to fix them!! Luckily I had a full system backup which was taken before unlocking. I switched back to X3 and I restored it. That was a week ago and all is fine.

Is this the worst case scenario? A CPU which appears fine, runs any stress test you like but slowly and quietly knackers up the system?? Anybody else had something similar happen?

 

[eddyc]

I have never heard of that. And have had no problems with my unlocked 550.

I cant see how the cpu would cause the errors even if it was dodgy. Prime95 runs checks to make sure that the cpu is not making mistakes in its calculations so it would have flagged those up if there had been a problem.

I will be interested to see what other people say though. I am sure this is an issue that affects lots of people.

 

[arknor]

you should run memtest

 

[PhoenixUK]

The errors might show up during the OC process when you're still working on your clock and get a lot of instable crashes. After you find 100% rock solid settings it should be fine....
Been running OCed CPUs since 486 times and never had any issues like that after you had a stable clock.

 

[pswfps]

Hi - yeah memtest is fine too. TBH if RAM was playing up I'd have expected Prime95 blend to have flagged that up, but I did run memtest too. And the Everest stress test BTW.

Anyway I'm back on 4 cores again now, 3.4GHz @ 1.425V so not exactly pushing it. All seems solid enough so we'll see if I get a repeat performance!! Could be the disk drive going flaky on me of course. Just seemed a coincidence after using it as a tri-core for 12months without any system issues at all then this.

And I can't help but wonder why AMD locked the core in the first place.

 

[eddyc]

Post back if it goes wrong again. Id be interested to know.

Good luck

 

[pswfps]

Will do. Thanks.

 

[Mr.Fantastic]

Really sorry to steal your thread pswfps.

I have the same cpu but my mobo is ASUS M3A78-EM, does any know if the 4 core can be unlocked with that mobo?

Thanks in advance.

 

[eddyc]

There is a list of compatible mobos in this unlocking guide. It is not exhaustive though so dont despair if yours is not on there.