Phenom II x3 720 system

blaineoliver · 13 Aug 2009 at 19:45

I have:

Phenom II x3 720.
Gigabyte GA 790XT UD4P
2x2GB Crucial 1333 CL9 1.8v DDR3

I cannot for the life of me get it stable. I can get the extra core, but that doesnt seem to be stable at any overclock between 3.4-5.

I have got the system stable at 3.4GHz with ram on stock settings. NB upto 2400 and HT upto 2400 and with 200 fsb. With 0.1 on NB, 0.175 on NBVID and 0.1 on SB.

This was stable, but the system is odd. I can overclock to 4ghz and post on it, but its not stable, how can it then not be stable down at 3.5ghz when it posts at 4. I have the core on 1.5v atm and that gives 3.4 stable.

Any advice? Ive been tinkering solid for a few days.

blaineoliver · 13 Aug 2009 at 19:49

Failed on stable settings now on prime blend test.

Pneumonic · 13 Aug 2009 at 22:50

I would make sure that your RAM and NB are 100% stable with your CPU at stock.. run blend for a good 3 - 4 hours.. saying that your voltages look about correct (NB wise).. I tend to keep profiles saved in the Bios of stable RAM then RAM / NB and then the final clock

I think your CPU voltages are to high these AM3 CPU are funny things

If you are sure your RAM / NB is stable then drop the clock to back to where you know its stable and then I would look at doing slight vcore increases.. if no effect then drop the vcore back and give the NBVID a bump.. you are "safe" up to around .250 - .275 increase.

Finally temperature plays a big part in stability much over 60c then there is the possibility of some random instability.. It may also be worth running your RAM @ 1066mhz and see if that helps.. UDP4 I had didn't like anything over that

blaineoliver · 13 Aug 2009 at 23:20

I dropped everything back to standard.
I got to 3.4 with stock volts, and am on 3.5ghz with 1.5v currently, with extra core enabled, it gave me 30 mins prime stability, so im happy. The ram is running perfectly, did another 30 mins prime blend on that. I am peaking at 60/62 degrees, might peg back to 3.4ghz and keep i there till i get a better cooler. I tried underclocking ram, couldnt get the timings might tigher, but im going to see if the ram is stable, at higher speeds, ive had it post easily at 1600mhz with 9-9-9-26 2T timings.

[ESRA]Taf · 14 Aug 2009 at 10:08

I had a similar issue to you, with my unlocked 550 BE and the exact same motherboard (make sure you're using at least BIOS version F4 or higher btw).

The first thing you should know is that changing all BIOS settings back to default does NOT properly reverse the core unlock, the only way to do that is to reset the CMOS with the jumper/switch on your motherboard. So try this and then see if it's stable - if not then it could be RMA time...

Secondly, do you have Cool & Quiet enabled? If so, you can either disable it, or read the thread I posted the other day about increasing individual voltages for each of the K10's three P-states. I found on mine that the "stock" speed of 3.1Ghz was actually stable, but one or more of the lower P-states was not when C&Q was throttling back (which is most of the time).

I assume you've run Memtest86 (or Windows 7's equivalent test app)? This will tell you if your RAM has any issues.

I also had an issue on mine where the CPU fan sensor on the motherboard seemed to be faulty, occasionally Windows would report that the CPU fan had failed with a BSOD 2 seconds after that - yet the fan was fine. I fixed this by disabling the CPU fan options in the BIOS, and setting it to always run at full speed.

And finally, what heatsink/fan are you using? I'm using the default AMD heatsink/fan that came with the CPU, and I discovered that with certain high overclocks, it would be stable to start with but then would become unstable as the temp passed a certain point - sometimes as long as 30 minutes after boot.

blaineoliver · 14 Aug 2009 at 12:49

Ok, i am definately going to look at the p-states, that could help, i can get stable upto 3.3ghz on stock volts, past that i have problems. I went back and turned hybrid off, and acc off to test 3 cores instead of 4. The ram is dissapointing, cant get it to prime stable at 1T. The bios is the latest, i think i will try disabled cool and quiet after trying your p states, thankyou for the advice, im going to run memtest as soon as ive looked at p states.