Basic overclock for a Phenom II X3 720

[djpandemonium]

I used to do a lot of overclocking back in the days of Athlon XP and P4 processors, but have been out of the game since then. I'm trying to catch up now, but feel a bit noobish. Thanks for your help and patience. :-)

 

I just built a new budget gaming system, specs as follows:

AMD Phenom II X3 720

Gigabyte MA790FXT-UD5P mobo

600watt OCZ Stealth Extreme

Powercolor ATI HD4770

4GB DDR3 Corsair TW3X4G1333C9

Vista 64 Home Premium

Antec Three Hundred case (3x120mm fans, 1x140mm fan)

Stock AMD fan/heatsink

 

The stock processor speed is 2.8Ghz. I read all over the internet that people are able to push these up to 3.2Ghz and 3.4Ghz with the stock voltage and cpu fan, and can go as high as 3.7Ghz with a better heatsink/fan and higher voltage. See here:

http://www.extremeoverclocking.com/reviews..._X3_720_14.html

and here:

http://www.overclockersclub.com/reviews/ph...0_810_am3/3.htm

 

I'm having trouble getting much of anything out of it, though. I bumped my multiplier from 14x to 14.5x (2.9Ghz), and ran Prime95 for an hour with no problem. Going another measly half multiplier (15x, 3Ghz) results in Prime95 errors on at least one of the cores within two minutes of starting a stress test. At 3Ghz my cpu temp is 42deg celcius idle and 55deg celcius under full load. I tried slowly increasing the core voltage from the stock 1.325v up to 1.5v, and it makes no difference. Windows seems stable, and I've even played L4D for a couple hours with the overclock, but Prime95 consistently errors.

 

Any idears what I'm doing wrong? Why can everyone else get to at least 3.2Ghz easily, and I can't get anything stable beyond a 2.9Ghz?

[Paradax]

As far as whats causing even small multi bumps to cause errors I'm really not sure since, as you pointed out, others are able to get it to 17+ (Although both of those reviews were running 1.5v+). However i have an old phenom I 9600 that would do pretty much the same thing and i found that enabling AMD's Advanced Clock Calibration at around 4% to 6% per core made a big difference so i would suggest trying that if you haven't already also try disabling AMD Cool n' Quiet and see if that helps.

 

Note: I looked in your motherboard manual and i didnt see Advanced Clock Calibration anywhere in the bios but it it has the 790 chipset with the sb750 chipset so it should have it and gigabytes product page advertises it so if you cant fid it you could try using AMD OverDrive and adjust it that way. I'd suggest using OverDrive as a last resort though cause if your settings are unstable it can be a pain to boot back up successfully.

 

Hope that helps,

-Paradax

[Paradax]

One more thing that i completely forgot to say,

 

Try OC'ing it with less memory and/or looser timings on the memory and make sure your bios is up to date.

[Guest ajmatson]

Can you post some pics of the settings in your BIOS when you are trying to overclock or are you using AMD Overdrive? The 720 can do a lot more however that cooler is really going to hold you back. The thermal threshold for the Phenom II series is 60C so that might be why a core is failing because it is getting hotter that that. Stock heatsinks do not evenly cool well.

[djpandemonium]

Thanks for the tips, guys!

 

My BIOS is up to date. I ran Memtest86+ overnight (8+ hours) with the overclock (3Ghz) to try to narrow down whether the instability is with the memory or the processor. It finished several iterations of tests with no errors. I took that to mean that my memory was solid as-is. Am I wrong? Should I be playing around with timings to see if that clears things up?

 

My mobo does have ACC. I had tried enabling it on Auto, but it made no difference. Let me play around with some settings on that and see if it doesn't make things more stable. If not, I'll get some pics of the BIOS (which is what I'm using to OC), and I'll post them up.

[djpandemonium]

I just finished messing with ACC. I ran p95 until a core (or two) would error, and then I would go into the BIOS and raise the ACC on that core +2%, reboot, and try again. Cores 1 and 2 are the ones that usually error, but core 3 did a few times. I got all the way to 12% (the max available) on cores 1 and 2, and 6% on core three, and was still getting errors.

 

I'm going to dink around with some of the cool & quiet settings, voltages, and if I can't make it any more stable then I'll post up some pics.

 

Interestingly, I am now using Core Temp to monitor the temp and individually core load, rather than Gigabyte's utility that I was using before. It seems more accurate. That, plus the fact that it's cooler right now in my office than it was when I first started this endeavor the other night, gives me new core temps. 36deg idle and 51max under full load. Typically I get an error long before it gets to 51 degrees, though. Usually they pop up somewhere in the mid-40 degree range. While I know this HSF is going to limit how far I can go, it doesn't look to me like temperature is the culprit yet. Feel free to correct me.

[djpandemonium]

Disabling cool and quiet pops up a warning about Catalyst drivers failing to load, followed a couple seconds by a BSOD.

 

Here are some screenshots of my BIOS. I think I got all the relevant stuff.

http://picasaweb.google.com/djpandemonium/Overclock#