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

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both of them can be unlocked, they're both quads with one core disabled anyway... only difference is that the 710 is basically a locked, lower speed version of the 720.
 
go into bios press Ctrl + F1 go into overclocking tweak at top you will see ACC( advance clock calibration set to hybrid and all cores.you will have 4 cores on reboot...
 


I thought you set them to "auto"? Are u sure you have the same mobo as me? (GIGABYTE GA-MA790FXT-UD5P)

oh wait, you have the UD4P one, but they both should be similar, i guess... anyway...

What clock speed and voltage was the tri-core at before you enabled the ACC option? I want something to start off from, since i have it at 3.2 Ghz at stock voltage, do i have to up the voltage to unlock it?
 
I'm ordering a 720 right now for my first computer build.

Would you recommend trying this? Does it void the warranty? Does is reduce the CPU's lifespan?

I'm very leery of overclocking, and even more leery of enabling a "defective core."

I don't want to fry my first CPU within a year or two, because I do not have the money to buy another.
 
trust me, the 720 is very cool, especially when overclocked, even on the stock cooler.

mine's at 3.4 Ghz, with a 1.350 voltage, which is only a tick above normal. I'll say 3.4 Ghz is where it is at, you can go higher, but i'll recommend a better cooler. For stock, it's 30C at idle and 45C load (playing FSX, the most CPU intensive game i have)

but still, i'm on the fence about unlocking it, even though i bought it when it first came out (higher chance of success), but still... you never know, and taking apart the case and hitting the CMOS switch is a PAIN IN THE ASS if that's the worst-case scenario.
 
alright, thanks for the info on unlocking, but i'm still scared about doing it...

Any successful unlocker, what was your Ghz speed and voltage before you unlocked it?

right now i have it at 3.4 Ghz on 1.35 volt... should i clock back to 2.8 and leave the voltage the same?
 
Couldnt unlock my 4th core 🙁.. oh well i wasnt expecting it to when i bought the tricore. Still have my 710 clocked at 3.5 with 1.35 for a while but have it at 3.2 just to be safe.
 

Hey extreme! I have the Gigabyte MA790GP-UD4H mobo with the F3A bios. I set to ACC hybrid and all cores and i couldnt reboot. Also tried per core and normal/auto, still no luck. Got my cpu in may so i am probly just one of the unlucky ones unless you have any suggestions for me. Thank you.
 
I've used All cores and Auto.It actually works better on Auto more stable at high oc.On ALL CORES you can adjust the % of oc on each individual core. Wind down the 4th core if unstable..As for the bro with the 720 that crashes on boot with 4th core activated try cranking your vcore voltage up to 1.45 -1.5 and wind down your ram e.g if its 1600hz knock it back to 1333 if its 1333 knock it down to 1066 and make sure your ram voltage is set to ram specs not board specs.Same with your ram timings.At the moment ive got my ram set at 1.8 volts. 1333 hz 7,7,7,24.Corsair XMS3 1600 hz. Works best for gaming....Change your bios to F4 or f4g .Some bios don't work i've been told.I have tried these 2 and they work. :hello: :sol: :sol: :sol: :sol:
 


about the bios... does F3 work? if not, how do i do the Qflash trick? i would like to know... and is 1.4 volt ok for full unlocked processor?
 
Have to say i was pretty sceptical about this but....It works!
I have the Gigabyte MA790GP-UD4H and using the f3 bios.
I set the ACC to hybrid and auto and when i rebooted it now says that its a phenom x4 20, now none of the temp monitor programs that i have will show a valid temp but i definately have four cores working and seemingly stable at 3.5gig (just changing cpu multi to 17.5) and no other changes at all!
 
Well damn ! I have the same board and i cant unlock my 4th core. I must have one of the cpu's made after march 4th. I have tried just about everything. Hybrid ECC with auto ACC- all cores. per core. even tried going 0% up to +4 % down to -4%. I just got unlucky. Oh well. Im stable at 3.717Mhz at 1.408 voltage. Wish i could get that damn core to unlock though.
 


Umm.. 790GX is not a chipset, its the name of the northbridge / SB750 is what you need (ACC) in order to unlock and Biostars are not the best for unlocking.. To my knowledge they are low end boards.. The top unlockers are Gigabyte UD3P's/Asus M4A79/MSI 790FX-GD70....
 


Well not all 720's will unlock the 4th core. Its basically a 50/50 chance as far as the 720's. The x2 550's have a higher unlocking rate 80-85%....
 
I have the Gigabyte MA790GP-UD4H with the SB750 and i just didnt get lucky unless there are other things i can try. I havent looked at the manufacturing date of cpu so i dont know if its one of the few or not. But i have seen a few people with my board that have been able to unlock 4th core. I just dont think there is anything else i can try. I have the F3a bios. Is there a wasy i can knock it back to the F2 bios? I've seen people have alot of luck with that version.
 
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.
 
Dude, 3.6 stable (3 cores) what more do you want? Thats sweet... Dont worry about unlocking the 4th core. I bet you dont even max out those 3 cores unless you are doing some mad rendering or cinebench.

As far as gaming is concerned your 720 at 3.6 should be more than enough.
 
That is all i do is gaming pretty much. A little bit of home movie making but not much else. Thank you . This is my first build so im pretty happy. I just found out that the EPP on my OCZ DDRII 800 memory lowered my timings to 4-4-3-15 and boosted it up to 412Mhz with no errors with 100% coverage on memtest too. Woohoo:)
 
That is correct, EPP in bios works wonders for gettin the most out of your ram. The only thing I would do as far as your ram is : go into Bios and change the 3 for a 4 meaning you should end up with 4-4-4-15. That should be the most stable setting as far as your OCZ ram goes....Let me know if you need any help....
 
Thanks again. I will change it right now. Would 4 more gigs do me any good ? I was thinking about getting 2 more sticks. Or should i consider 1066 ram ?
 
Ok so here is the deal, if your OS is 64 bit then YES you should upgrade to 8 gigs, if not then 4 gigs is basically the max you can use on a 32 bit system. As far as 1066Mhz ram, i would not invest 60-80$ just to bump my speed up a tad. 4 GB of 800MHZ ram should be fine. If you have the money to burn then go ahead but you wont see a night and day difference. I would save up for a future build and then get some DDR-3. I have 667, 800 and 1066 ram and I do see a significant difference when we compare 667 to 1066 but from 800 to 1066 you really wont be amazed at the speed diference.
 
I do have Vista 64. And i can 4 more gigs of the same ram for 40 bucks. And a future build is definitely coming so i think i will take your advice. I have very much enjoyed the experience and am looking forward to building another. And everyone on Toms have been great with me from the begininng. I had some pretty noob questions when i started. Thank you for your input.
 
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