How do i unlock 4th core on Phenom II x3 720?

[4745454b]

Yeah, forgot to mention that in my post. If you can get to 3.6GHz on 1.375, or 1.45, why use 1.5? Its more voltage then YOUR system needs, which is only turned into heat and a shorter life for the chip. If you found the max frequency for your chip, you now need to find how little voltage you need to achieve it. Don't just use the max and leave it there.

 

[Chronobodi]

i tried it... no luck, had to reset CMOS...

did Auto ACC, nada.
did All Core, nada.

finally, did all core from -12% to +12%, won't POST.

 

[alershka]

I just enabled the fourth core yesterday. I am running all four cores at 3.2 ghz with ddr2 800 mhz memory and stock cooling.

When I run Prime95, the fourth core bombs almost immediately with a rounding error. However, I've run the heck out of the pc with all four cores (Crysis at 2048 x 1152) and I haven't had any problems. Should I be concerned?

I haven't changed any voltages or overclocked any other components. Any suggestions? I'm running an Asus M4N72-E running the latest bios (1302). I have four gb of Corsair xms and 2 gb of Crucial Ballistix. I'm running Win7 Home Premium X64.

Thanks.

 

[Kuvlai Khan]

thanks OvrClkr. I will check for a newer bios. I think im just out of luck. Im sitting at 3.6 stable on 3 cores so im not too dissapointed right now.

Actually the highest BIOS Version for Gigabyte 785G/790GX Chipsets is now F7... I have a GA-MA785GM-US2H motherboard with Athlon II X2 245 CPU. Also, is my CPU unlockable to 4 cores?

 

[Guest]

Yeah, but where is the fun in that?

yes... not the other word... I am British... speak correctly

 

[4745454b]

Tamato? Lucky for me I'm American, so no worries😀

 

[Chronobodi]

k, i unlocked it, finally...


HOWEVER...

it runs fine on stock clocks and volts, but i try to run it on 3.2 ghz, it explodes when i try Prime95 right at the get go.

so, that core needs too much volt for so little speed?

 

[RazberyBandit]

Congrats on unlocking it. I just unlocked my 720BE after almost 9 months of ownership

Did you bother to Prime95 test it while everything was set to the stock speeds? (14x multiplier, 200 MHz FSB, and 1.325 Vcore) If you didn't, I suggest doing that first. If it passes a several hour run of Prime95 Small FFT tests, then it should be OK to attempt overclocking it. If it does not, then unfortunately your 4th core is not stable and you should revert to your previous 3-core BIOS settings.

I had to increase my voltage to 1.350 to get mine stable at 3.2 GHz. That was only a .025 V increase... Nothing major at all. That's actually the stock voltage for the 955 BE, which runs at 3.2 GHz. Fancy that!

 

[JofaMang]

My 710 was a leaky hog, and even as a stock triple, needed 1.4v (+.075) to run 3.4ghz, and couldn't stabilize 3.6ghz without breaking 1.525v. I unlcoked it for about 2 hours on a friends new build, and it needed 1.4v to stabilise as a quad at stock speeds (2.6ghz), and 1.475v to run it at 3.25ghz. I didn't have the time to do much more than 45mins of p95, but it passed, hot as hell (by my standards, anyhow) at 62c on my old hsf.

 

[4745454b]

Ouch. Is 1.4 or 1.5 as high as your supposed to go? Doesn't sound like a good chip at all.

 

[RazberyBandit]

1.5 is usually the point you "shouldn't" cross on Phenom II's. I try my best to limit my OC's to 1.425 - 1.45 to try and avoid crossing the breaking point. I usually get 500-700 MHz increases in that range, which I consider respectable.

Some chips, like 550BE's, OC really well while still below the 1.4V mark. In dual-core mode, my brother's 550 is sitting at 3.71 GHz (18 x 206) at 1.350V. Makes me wonder how high it "could" go if really pushed.

 

[JofaMang]

Ouch. Is 1.4 or 1.5 as high as your supposed to go? Doesn't sound like a good chip at all.

I think a lot of it has to do with my motherboard, to be honest. My 965 needs more volts for stability than most people once i cross the 4.0ghz range. I keep it at 3.8ghz for daily use, and have stopped pushing my OC limit until I replace my mobo. I hope things improve some, or else it appears I just got horrible luck with CPUs.

The Phenom IIs recommended voltages go up to 1.55v. My 4.321 run was set at 1.55v, 1.536 effective. My daily is only running at 1.41v, still kind of high for 3.8ghz on the c3 chips.

 

[touthoj]

I unlocked my 720 BE to 4th Core with Motherboard ASUS M4A785-M i bought this just two days ago, got it working OC it 3.4ghz on Air with Big Typhoon HSF and 4 Case Fan. i can hit 3.6 but i have to up volt so i didnt want to do that but its running PERFECT. Prime Test it for 8hr fine. now i just need to get a new Video Card like 4850 cuz im low on budget and some new DDR2 ram. hope this help, oh yeah, i also UPDATE the bios after to the latest 0702 and it still works, i Unlock it with the 0503 Bios version then update new bios and it work. THanks for reading.

 

[vandreadstriker]

Hi, Sorry if this is a 'noob' question but I was just wondering, does some of your unlocked 720 by any chance locks it self sometime?

I'm running my 720 on ASRock M3A790GXH/128M and am able to unlock it but sometimes it locks itself and I'll have to go to BIOS and disable the ACC, restart it, then enable ACC again...

Oh and btw, my batch number is 0904

Thanks

 

[Motopsychojdn]

Thats not your chip locking itself again, I suspect your system is resetting to default cause somethings not right,

 

[vandreadstriker]

yeah, my computer sometimes won't boot and needs to reset 2-3x before booting and i hve no idea why... does that count?

 

[4745454b]

almost sounds like a dying board/bios. You might want to replace. Not sure about this though.

 

[vandreadstriker]

almost sounds like a dying board/bios. You might want to replace. Not sure about this though.

kay, thanks, I'll try to update my BIOS

 

[vandreadstriker]

wait, I just remembered, I overclocked my 720 to 3.1Ghz and when it locked itself, the multiplier & voltage are still the same and the ACC was still on 'Auto'

So I don't think that my board's dying..

 

[simon12]

Sounds like I got lucky I don't really know what I am doing just read a few guides and unlocked the 3rd and 4th cores on a 550BE and overclocked to 3.5GHz just on the multiplier using 1.3875V and it runs Prime95 for over 2 hours fine and temp only gets to 49C max (32C idle). 3.6GHz looked stable @ 1.4V but crashed after 1.5 hours of prime95 with temp @ 44C max and voltage increases sent the temps soaring. I am just testing at the moment if I can get back to 3.6 on the frequency amd so far Prime95 has been running for half an hour fine with temp still 49C max. If anyones interested my hardware is:
Asrock 880G Extreme 3 (The cheapest MB with the features I wanted)
AMD Phenom II x 2 550 BE now X4 B50
Coolmaster Hyper TX3 cooler

 

[isamuelson]

Well, I'm running at 1.5v (the Black Edition OC guide sticky in this forum says that's the highest you can go safely). I only had to up the voltage to get it to 3.61 ghz. Otherwise, I can OC to about 3.2ghz without upping the voltage when running all four cores on my 720 BE.