Advance Clock Calibration

[dwisen]

this is a pic of my bios options on a
GIGABYTE GA-MA785GM-US2H AM3/AM2+/AM2 AMD 785G HDMI Micro ATX AMD Motherboard

I have unlocked all four cores of a phenom ii x2 555 but the 4th core is unstable and crashes windows when i put it under any stress like benchmarking.
the 3rd core runs fine.
i can even overclock cores 1-3 up to 3.82Ghz on air and it run absolutely stable and beautifully.

i have adjusted voltage from min-max recommended to get the 4th core stable and that does not work.
i am not yet willing to accept my 4th core is in fact a dead/unusable core.
if the 4th core was really dead normally it would fail to POST or even boot windows
would an under clock on the cpu help?
someone suggested to cut my FSB from 2600MHz to half that, but im not sure how to or how that would even help.
4 cores running half speed seem the same as two cores running full speed, am i right about this?


i am mainly wondering what the (core 0) -2 / (core 3) -2
options are all about and if i adjust that only on the 4th core or even all cores what the result would be.
does anyone even know what those options do?


Thanks ahead of time

 

[dwisen]

i found this on another website

Hmmm I am inclining to share the same notion.

When I was trying to make the failing core stable, I increased the ACC to +2 for that core and it worked perfectly BUT then the next core would start to fail when it was not failing before. For instance, my ACC is set to 0,0,0,0. During overclocking, core 1 kept failing. I then set ACC values of 0,2,0,0 BUT THEN, core 2 started failing instead. The next set of values that seemed logical for me to try were 0,2,2,0 = Core 2 failed. I am going around in circles 0,2,4,0 = core 2 failed. 0,4,2,0 = core 2 failed again. I am lost.


KEY:
ACC values corresponding to Core 0, Core 1, Core 2, Core 3 are 0,0,0,0 respectively for the above example.
Last edited by sandeep; 10-08-2008 at 08:23 AM.

 

[amnotanoobie]

Maybe the fourth core is really faulty?

The 3-core 3.8GHz would be a hell of a lot better than a quad-core at half the clock speed.

 

[firstmm5]

You said that you are not able to accept the fact that the 4th core is no good, why, because you are a stubborn fool. Think about it! AMD thoroughly tested the cores and determined that the 3rd and 4th cores where no good. Yet you seem to think that AMD does not know what they are doing.
Listen, it is a crap shoot! Sometimes you get lucky, and sometimes you don't! YOU SHOULD BE HAPPY THE 3RD CORE IS WORKING AND LEAVE IT AT THAT! If you want a 4 core CPU, then try a Phenom x3, or Phenom II x3, and try unlocking the 4th core.

ACC and its codecs are a poduct of AMD and, and has been subsequently shelved by AMD, i.e. AMD does not officially support it. Instead they have released an Overclock/ Overdrive utility, that can be used to unlock the cores. Gigabyte advises using it with their MBs, utilizing the AMD 785 chipset.
see http://www.gigabyte.com/products/product-page.aspx?pid=3447#ov
also http://game.amd.com/us-en/drivers_overdrive.aspx
I got an AMD Phenom X3 for $42 on ebay!
Phenom II has more energy efficiency, an extra L3 cache, and uses DDR3 memory. I think that is the only difference.
DDR 2 memory is still very fast. Also, most AM3 MBs, support older Phenom Cpus.

 

[mindless728]

firstmm5, you all most had it, if you want a quad core, buy one, because even the x3's are a crap shoot, the x4's are guaranteed

 

[dwisen]

You said that you are not able to accept the fact that the 4th core is no good, why, because you are a stubborn fool. Think about it! AMD thoroughly tested the cores and determined that the 3rd and 4th cores where no good. Yet you seem to think that AMD does not know what they are doing.
Listen, it is a crap shoot! Sometimes you get lucky, and sometimes you don't! YOU SHOULD BE HAPPY THE 3RD CORE IS WORKING AND LEAVE IT AT THAT! If you want a 4 core CPU, then try a Phenom x3, or Phenom II x3, and try unlocking the 4th core.


hey man thanks for the reply with an honest answer but maybe tone it down a bit ehh? i mean after all did i come to a thread you started and call you a stubborn fool? or worse? no i didnt.
this is a HELP forum and i needed and answer to my question, does not make me an idiot. even the most brilliant minds need help every so often you know....


i AM happy with my 3 cores and never said AMD did not know what they were doing or that i was not happy.
all i did say was it could be a small possibility that my mobo or power supply may be the problem in fully unlocking the thing and getting it stable, which i was right!
popped it into another mobo and BAM all 4 cores NO PROBLEM!

but that mobo is not mine so im stuck with 3 cores and quite happy at the moment knowing that i have a 4core under the hood.
besides that point, im selling it soon and getting the 6 core phenom.

 

[Guest]

I have some experience unlocking 4th core on Phenom II x 555.

I have two boards; MSI 785G-E51 and Biostar TA870+. Both unock both cores three and four to become Phenon II X4 B55 on CPU-Z.

However, I can get over 5000 passmark cpu score fairly easily wiht MSI 785G-E51, but with the Biostar TA870+ windows 7 hangs very frequently even without overclocking and was unusable with 4th core unlocked but ran fine as x3 core.

I returned them to Fry's for exchange and tried again with the exact same results with the new Biostar board and X2 555 cpu.

 

[Guest]

I just want to be clear that I was using the very same cpu and getting the ddferent results based on which board it was installed in - stable and highly overclockable wiht 4th core unlocked while in the MSI 785G-E51 and when installed in the Biostar TA870+ totally unusable with 4th core unlocked.

I was thinkingabout returning the biostar TA870+ combo to Fry's and trying the new Fry's combo Phenon II X2 555 and GIGABYTE GA-880GA-UD3H AM3 instead but I wonder if it will just be like the Biostar board.

 

[dwisen]

from what i can tell the GIGABYTE boards are being labeld as some of the best core unlockers. ASUS are also being rated well but im not a big fan of ASUS. i think the problem with my board is its on the cheap side of the GIGABYTE spectrum but i bet if i invest in a higher priced model i would do just fine. afterall i have already proven that the 4th core unlocks and that it can be stable with a different mobo.


munch on that firstmm5

 

[Guest]

OK.

With that I decided to give the Phenon II X2 555 and GIGABYTE GA-880GA-UD3H AM3 combo a try. I'll let you know what happens.

Returned the Phenon II X2 555 and Biostar TA870+ because it is pointless without the 4th core.

I think an Athlon II x3 435 unlocked is better that an Phenon II X2 555 without the 4th core. That's what I've been running in the MSI875GM-E51, the Athlon II x3 435 unlocked as a Phenon II x4 B35 overclocked and it's pretty good.

 

[dwisen]

the 435 is not a bad processor but keep in mind that a phenom II x2 555 Be unlocked with all 4 cores is a phenom II x4 955 that majorly out performs the athlon.

i would keep the x2 unlocked to an x3 or at least get a 955
the x2 phenom is about equivalent to the phenom x3 720 and in some cases out performs it.
when making the build i have now it was a choice between the x3 or the x2 and i went with the x2 just for that reason

 

[steveC07]

Understood.

I just prefer an unlocked Athlon II as a Phenom II x4 B35to any tri core or duel core, even the X2 555 black.

I really like the x2 555 black though when you get a good one and unlock it.

My problem has been that I've only been willing to buy a Phenom II x2 %%% black as a Fry's combo and I have tried three of them before I got one that I am happy with the board it came with. The 1st two I returned due to very poorly matched boards that wouldn't do what they were suposed to - unlock both cores successfully - but finnally I Fry's has a good combo deal for x2 555 cpu and gygabyte board.

The current Fry's $129 combo with x2 555 black and gigabyte 880GA-UD3H turns out to work really good if you get a good CPU.

I did get a good CPU and and have overclocked it to 4007 mhz with voltage boost and it has performed the passmark cpu tests at 4007mhz without crashing for a score of 5270. I'll set it to 3850mhz and never worry about it again. Thats good enough for a passmark score of 5000 all day long and that is pretty fast for a cpu I paid $51 for. The board was $78. Thats hard to beat!

Don't know about other aspects of the gigabyte 880GA-UD3H , but I'd say it is very good for overclocking an x2 555 black. Better that the MSI 785g-e51 which does not allow voltage changes in the bios. And a Biostar TA870+ forget about it.