Unlocked Phenom II X2 550 - some issue

[Zorander]

Hi all,

I recently unlocked all 4 cores on the 550 with seeming success but am encountering odd sound-related issues in some apps. Internet browsing, Office and general activities run fine. Sins of Solar Empire and Supreme Commander run smooth. However, GTAIV suffers sound-related issues: FX sound cutting out and ambient sounds playing in endless loops. MPC-HC also crashes unless I direct its sound output to 'MPC Audio Renderer' (DirectSound & WaveOut result in a crash). Windows generally run rock stable otherwise.

I cannot say for sure if I have an healthy core or if my soundcard is not co-operating nicely in this 'unlocked' state or if this is something else. I simply unlocked the cores by enabling ACC and Hybrid BIOS mode. No overclocking. Spec of the system below:

AMD Phenom II X2 550
Gigabyte GA-MA785GT-UD3H (BIOS: F9B - same success/issue with F4)
2x2GB DDR3 RAM
HIS HD5750 1GB GPU
E-MU 0404 Soundcard
450W Antec TruePower PSU
Windows 7 Home Premium
Wi-fi PCI card, 500GB HD & DVD burner (I doubt they matter here)

I'm suspecting the soundcard here but perhaps someone has experienced similar issues here and can share their experience with me.

Thanks in advance!

 

[Uppsala9496]

Run something CPU intensive like Prime95 or Folding@Home and see if you get any errors/crashes. I'd let it run for about 24 hours if possible.
If it runs clean with no issues, then move onto the next possible item (soundcard).

 

[Zorander]

Thanks for the suggestion. Quick question: for Prime95, which test (small FFT, large FFT, Blend) would be best for testing the CPU?

Thanks.

 

[betasub]

Small FFT is less reliant on other components (RAM, motherboard, PSU) than the other tests.

 

[Zorander]

Some update: I have run the Small FFT test for 30 minutes with no problem. I have also played DiRT2, Medal of Honor (2010) and Civilisation V as the unlocked quad-core with no issue. Fallout NV occasionally crashes but not often enough to frustrate. The sound issues still occur even when I revert to on-board sound.

I recently tried disabling the 4th core, ie. running as tri-core, and interestingly none of the issues are occuring. I have been running this way for a few days and so far so good.

I think the 4th core is 'not perfectly' healthy: Windows and most apps will work fine on it but it is probably 'disfunctional' on a few, specific math processes. Would I be on the right line here?

Regards.

 

[Skurge]

You could try upping the voltage just a tad. see if that helps.

 

[richierich1212]

sounds like a soundcard driver issue.

 

[ssshjp]

You may try to update your sound unit driver.

 

[douglasb]

Try running as dual core (without the other cores unlocked) and see if you experience this same problem

 

[frostedflakes]

As others have mentioned, you could try giving it a bit more voltage, could get that fourth core stable.

30 min isn't really long enough for Prime95 IMO, let it go for a long time (24 hours or so). If your CPU can get through that without any errors, I'd be pretty confident in saying it should be completely stable for about anything you can throw at it. 30 min really isn't enough to reveal minor stability problems, though, I've had situations where a system was seemingly stable but still had weird issues occasionally. Running Prime95 for an hour or two wouldn't pick them up, had to run it for an extended period and it wouldn't report an error until like eight hours in.

 

[Zorander]

What sort of voltage increment should I apply? I can see from CPU-Z the Phenom runs on 1.4V stock voltage (drops to about 1V on idle).

Also to be clear, I have none of these issues running as tri-core (unlocked 3rd core), not to mention as dual-core. It's the 4th core that seems suspect.

Thanks.

 

[repoman0]

Personally I'd only add about .05V to what you're already running, just to keep heat under control, especially as a quad core. Anything more probably won't be worth it. You might consider just working with three cores and overclocking a bit more, since chances are if it's working now the clock freq. can go higher - seems with the fourth core, you'll always be working at the edge of stability.

My X2 555 is the same way, the first three cores run great at 3.2GHz and low volts (a little under 1.25V) but to get the fourth core working, it takes ~1.35. I choose to run with three and reduced heat, and if I need more, I'll buy an X4 or X6 in a couple years.

 

[SickBeast]

Try disabling everything except the "faulty" core and see if the problem persists (if you can).

 

[Zorander]

Tried upping the CPU voltage in +0.05V increments up to 0.15V increase. It only postponed the sound issue, i.e. takes a while longer for GTA4 audio to stutter and MPC-HC to crash. I'm not comfortable with increasing the voltage any further (should I though?).

OTOH, I am experimenting with upping the clock speed in tri-core configuration (love this unlocked multiplier thing) What speeds can I expect to achieve with the 550? I am using the Xigmatek HDT-S1283 cooler (primarily meant as quiet CPU cooler).

Thanks.

 

[SickBeast]

What voltage are you running at?

1.5v is the safe maximum apparently. I run mine at 1.53v to maintain stability at 3.8ghz and everything seems fine so far. If my CPU blows up I'll just get an X6 so I don't really care, though.

 

[Zorander]

I am maintaining 3.6GHz Tri-core at stock voltage. Max temperature under Prime95 stress-test maxes out at 65-66C with 29-30C ambient temp (is that good or bad temp?). It has been stable so far and I don't think I'm going to try pushing it further (won't risk damaging the CPU especially since it is performing more than adequately for my needs now).

Pity that 4th core is not 100% reliable on certain applications but I suppose a solid, overclocked tri-core config is a good enough consolation prize.

Cheers!