How to enable 4 cores on Phenom II X3 CPUs

[runn3R]

Hello All

Certain Phenom II X3 CPUs (710, 720) can be enabled to work with 4 cores instead of 3 as default. This gives up to 25% performace gain, for more details check here.

  How to do this trick?

Enter BIOS SETUP sceen by pressing DEL
Press CTRL + F1 key to show all hidden options in BIOS
Go to sub-menu "MB Intelligent Tweaker (M.I.T)"
Change option "Advanced Clock Calibration" from DISABLED to AUTO
Save the changes and exit.

UPDATE: have a look at the presentation with details:
http://forum.giga-byte.co.uk/index.php/topic,328.0.html

Here is the list of supporting motherboards and bioses. These bioses are available at our official website at: http://www.giga-byte.co.uk/Support/Motherboard/BIOS_List.aspx

GA-MA790FXT-UD5P  -  F3b
GA-MA790XT-UD4P    -  F2b
GA-MA790GP-UD4H   -   F1
GA-MA790FX-UD5P   -   F1b
GA-MA790X-UD4P     -   F2b
GA-MA790X-UD4       -   F2a

Good luck!    Don't forget to feedback us your results.
 

[Badbonji]

There have been people trying it on OCForums, and so far most come into stablity issues, even at stock speed. However, people have been able to overclock with the 4 cores all enabled which look promising.

[Hybrid]

I tried the ACC trick with a GA-MA790X-UD4P with F2B bios and a Phenom II X3 720 and it doesn't work, when ACC is on "auto" or "per core" mode, the system doesn't boot. Maybe my fourth core is not working.

[Hybrid]

I tried the ACC trick with a GA-MA790X-UD4P with F2B bios and a Phenom II X3 720 and it doesn't work, when ACC is on "auto" or "per core" mode, the system doesn't boot. Maybe my fourth core is not working.

I've a GA-MA790XT-UD4P, sorry for the mistake.

[Badbonji]

Well some of the 720's are 940's with less cache and one disabled core, this could be due to meet demand or that one core was bad so they disabled one. The ones that are just to meet demand will work fine, whereas the ones with bad cores will have stability issues or fail to POST, which is what is happening to you. It is just luck for now whether you get a good cpu or not which works with all 4.

[runn3R]

i have information about success in completing above procedure in cpus that have been produced in 4 th week of this year - marked as "0904". but probably there are also some other batches of cpus that could be enabled

[Hybrid]

My 720 is a "0904"
I retried the ACC trick with +0.050V at VID and now the system boot! But no 4th core in windows... very strange, I suspect that the new f2b bios published the 03/10 block it. The F2 bios also have ACC when CTRL+F1 is typed but it doesn't seem to be effective whatever the voltage.

[xiant]

I tried the ACC trick with a GA-MA790X-UD4P with F2B bios and a Phenom II X3 720 and it doesn't work, when ACC is on "auto" or "per core" mode, the system doesn't boot. Maybe my fourth core is not working.

well, I did it and it does work for me. when I restart the computer it shows Phenom II x4. ...but I need to up the voltage because the computer is not stable.... so I prefer to come back to the classic X3

[bytheway_r]

Heh, I didn't even know there was a thread like this here.

My x3 720 unlocked without any problems and works fine at stock voltage ( actually, it's stable at 1.200v @ 2.8Ghz ) on GA-MA770T-UD3P rev. 1.0 with any bios I've tried. When I need it, it runs at 3.5Ghz @ 1.4125v. Let's just say I'm very pleased with it.

[Dark Mantis]

Heh, I didn't even know there was a thread like this here.

My x3 720 unlocked without any problems and works fine at stock voltage ( actually, it's stable at 1.200v @ 2.8Ghz ) on GA-MA770T-UD3P rev. 1.0 with any bios I've tried. When I need it, it runs at 3.5Ghz @ 1.4125v. Let's just say I'm very pleased with it.

That's why we always encourage members to do a search for whatever their interest is before asking a new question. Very many topics have been covered before.