Unlocking Athlon II / Phenom II cores and L3 cache

AMD K10 family includes 12 desktop Sempron, Athlon II and Phenom II families, which differ from each other by the number of cores - from 1 to 6, the size of L2 cache - 512 KB or 1 MB per core, and the size of L3 cache - from 4 to 6 MB L3 cache or no cache at all. It's interesting that this variety of microprocessor families with different features is derived from just four base cores:

  • Regor - 2 cores, 1 MB L2 cache per core, no L3 cache
  • Propus - 4 cores, 512 KB L2 cache per core, no L3 cache
  • Deneb - 4 cores, 512 KB L2 cache per core, 6 MB L3 cache
  • Thuban - 6 cores, 512 KB L2 cache per core, 6 MB L3 cache

All other K10 cores are created from 4 base cores by disabling one or more CPU features. For example, Athlon II family is based on Regor, however it has one CPU core disabled. The table below summarizes what features are disabled for which family:

FamilyStandard featuresBase coreDisabled features
Athlon X2
Models 5000 and 5200 only
2 cores
2 x 512 KB L2 cache
No L3 cache
Deneb3rd and 4th core

6 MB L3 cache
Single-core models
1 core
1 MB L2 cache
No L3 cache
Regor2nd core

Athlon II1 core
1 MB L2 cache
No L3 cache
Regor2nd core

Athlon II X2
2 cores
2 x 512 KB L2 cache
No L3 cache
Deneb3rd and 4th cores

6 MB L3 cache
Athlon II X3
3 cores
3 x 512 KB L2 cache
No L3 cache
Deneb4th core

6 MB L3 cache
Athlon II X3
3 cores
3 x 512 KB L2 cache
No L3 cache
Propus4th core

Athlon II X4
4 cores
4 x 512 KB L2 cache
No L3 cache

6 MB L3 cache
Athlon II X4
4 cores
4 x 512 KB L2 cache
No L3 cache
Thuban5th and 6th core

6 MB L3 cache
Phenom II X2
2 cores
2 x 512 KB L2 cache
6 MB L3 cache
Deneb3rd and 4th core

Phenom II X33 cores
3 x 512 KB L2 cache
6 MB L3 cache
Deneb4th core

Phenom II X4 8xx series
4 cores
4 x 512 KB L2 cache
4 MB L3 cache

extra 2 MB of L3 cache
Phenom II X4
4 cores
4 x 512 KB L2 cache
6 MB L3 cache
Thuban5th and 6th core

Identifying underlying base core is easy from the markings on the CPU. The first (line) line of markings contains family name. The second line has OEM part number. The third line, highlighted on the picture below, contains stepping code:

Identifying AMD base core

One of the most important parts of this line are two letters in the middle. These letters are used to determine base core:

  • AC - Deneb
  • AD - Propus
  • AE - Regor
  • CB - Thuban

As an example, the pictured Sempron on the picture above has "AE" letters, i.e. it is based on the Regor core, and, as such, has one CPU core disabled. The pictured Athlon II X3 has "AD" letters, which means that the base core is Propus.

There are two major reasons why certain features are disabled on AMD processors. Cache memory and extra cores on these microprocessors could be disabled due to internal core or memory defects, or to meet market demand. Unfortunately, it's not possible to tell whether the features were locked down because the core or cache memory didn't pass quality assurance tests, or because high-profile OEM company needed a large number of cheap parts with fewer cores and/or smaller size of cache. The good news is that often it is possible to unlock the disabled features. To do this go into BIOS, and look for "Advanced Clock Calibration" feature. It's very likely that you will find it in Advanced tab on the "CPU Configuration" screen. Set this feature to "auto" and reboot the computer. If the computer hangs and doesn't want to post then clear CMOS memory. If it still doesn't work you may try to increase the core and NorthBridge voltage a little bit. Be careful with voltage increases - running the CPU outside of specifications will void your warranty. Once you have the core and/or memory unlocked, run memory and CPU intensive test to confirm that the CPU indeed doesn't have any noticeable defects. We've heard a rumors that unlocking CPU features may kill the CPU and/or motherboard, but we've never seen a proof of it. So far we tried to unlock from 20 to 30 processors from different Sempron, Athlon II and Phenom II families, and in the worst case we had to reboot the system. In our experiments we've seen more than 50% success rate. Your mileage may vary.

Below is a list of different models that can be unlocked, and how BIOS identifies them:

Processor modelCPU name
Athlon X2 5000 (XXXXX AC)AMD Phenom(tm) FX-5000 Quad-Core Processor
Athlon X2 5200 (XXXXX AC)AMD Phenom(tm) FX-5200 Quad-Core Processor
Sempron 130AMD Athlon(tm) II X2 4300e Processor
Sempron 140AMD Athlon(tm) II X2 4400e Processor
Athlon II 160uAMD Athlon(tm) II X2 260u Processor
Athlon II 170uAMD Athlon(tm) II X2 270u Processor
Athlon II X3 400eAMD Athlon(tm) II X4 6400e Processor
Athlon II X3 405eAMD Phenom(tm) II X4 B05e Processor
Athlon II X3 415eAMD Phenom(tm) II X4 B15e Processor
Athlon II X3 425AMD Phenom(tm) II X4 B25 Processor
Athlon II X3 435AMD Phenom(tm) II X4 B35 Processor
Athlon II X3 440AMD Phenom(tm) II X4 B40 Processor
Athlon II X3 445AMD Phenom(tm) II X4 B45 Processor
Athlon II X3 450AMD Phenom(tm) II X4 B50 Processor
Athlon II X3 455AMD Phenom(tm) II X4 B55 Processor
Athlon II X4 620AMD Athlon(tm) II X4 620 Processor
Athlon II X4 640 (ADX640WFK42GR)AMD Phenom II X6 1405T
Phenom II X2 545AMD Phenom(tm) II X4 B45 Processor
Phenom II X2 550AMD Phenom(tm) II X4 B50 Processor
Phenom II X2 555AMD Phenom(tm) II X4 B55 Processor
Phenom II X2 560AMD Phenom(tm) II X4 B60 Processor
Phenom II X2 565AMD Phenom(tm) II X4 B65 Processor
Phenom II X2 570AMD Phenom(tm) II X4 B70 Processor
Phenom II X2 B53AMD Athlon(tm) II X4 553 Processor
Phenom II X3 700e???
Phenom II X3 705eAMD Phenom(tm) II X4 05e Processor
Phenom II X3 710AMD Phenom(tm) II X4 20 Processor
Phenom II X3 720AMD Phenom(tm) II X4 20 Processor
Phenom II X3 740AMD Phenom(tm) II X4 40 Processor
Phenom II X4 650TAMD Phenom II X6 1505T
Phenom II X4 805???
Phenom II X4 810AMD Phenom(tm) II X4 810 Processor
Phenom II X4 820AMD Phenom(tm) II X4 820 Processor
Phenom II X4 960TPhenom II X6 1605T
Phenom II X4 970 (HDZ970FBK4DGR)???

And, finally, CPU-Z screenshots of some unlocked processors:

Unlocked Athlon II X3 400e:

Unlocked Athlon II X3 400e

Unlocked Athlon II X3 405e:

Unlocked Athlon II X3 405e

Unlocked Phenom II X2 550 (C3 core revision):

Unlocked Phenom II X2 550

Unlocked Phenom II X2 555 Black Edition (C3 core revision):

Unlocked Phenom II X2 555 BE

Unlocked Phenom II X3 740 Black Edition:

Unlocked Phenom II X3 740 BE

Unlocked Phenom II X4 820 (not Black Edition):

Unlocked Phenom II X4 820


There are 52 comments posted

Maybe some error in the first table?

2010-04-30 11:40:19
Posted by: Howard

Athlon x2 should be Athlon II x2

Phenom II x6 9xxT should be Phenom II x4 9xxT


Response: You're right. The family names were corrected.

Athlon II x2 L2 cache

2010-04-30 15:48:16
Posted by: Howard

Athlon II x2 L2 cache should be 2x1MB , not 2x512kb.

Please verify.

Response: I shouldn't have changed Athlon X2 to Athlon II X2. So, Athlon X2 is correct, and it does have 2 x 512 KB L2 cache.

Whats going on ?

2010-07-08 18:26:16
Posted by: chaosmountain

I unlocked mine from what it say's here, but in cpu-z it shows 831mhz ??

Am i missing something here ?

I have a AMD ADX440WFK32GI Athlon II X3 440 Triple Core Processor - 3.00GHz, Socket AM3, 1.5MB Cache With a Gigabyte MA785GM-US2H Motherboard.

Whats going on ?

Response to chaosmountain

2010-07-24 09:43:15
Posted by: athlonlover

That's normal, because cool n quiet feature is on.

This list is a little misleading...

2010-09-25 19:10:08
Posted by: mrgerbik

Your Athlon X2 should read Athlon II X2 (with no 5000 number - unless you are referring to older 65nm Athlon X2's which aren't based on Deneb core). The base core for almost all Athlon II X2's should be "Regor"... BUT, some Athlon II's are based on a cut down Deneb core (*i am pretty sure*) are all CPU's with the "MBOX" at the end of the model number.

Also, any core with a "T" in the model name are based on newest "Thuban" core... so your 9XXT at the bottom of the list should have base core listed as "Thuban".

I came here to see which Athlon II X2's (no L3) are unlockable to Deneb (6MB L3) core.

Response: "Thuban" core for the 960T was corrected. Thank you! The 5000 model is advertised and sold as Athlon X2, not Athlon II X2. Your assumption about the "MBOX" is incorrect.

chaosmountain post

2010-12-13 23:02:47
Posted by: Steven

Thats your CPU's Cool'n'Quiet support running, disable in bios, could be called something else...

Declocks your CPU via motherboard multiplyers to save thermal heat and power.

Unlocked Athlon X3 445

2010-12-17 17:52:37
Posted by: Fernando Arauco

My unlocking went as a breeze with a ASROCK A790 GMH/128M, just put ACC to "AUTO" and that was it.
In addition itīs overclocked to 3.25 ghz.
Works 24/7 with stock cooler, I never shut off my PC, always connected. Couldnīt be better.

Unlocked Athlon X3 445


2011-08-25 19:11:09
Posted by: shamus_l

the Phenom II X3 turns into:

Phenom II X4 8700e

Phenom II 560 ==> B60.

2011-09-10 10:55:13
Posted by: Mos_Ilie

HDZ560WFK2DGM, CACDC AC 1051FPM, 9P17413A10496

Phenom II 560 ==> B60.


2011-09-10 10:57:28
Posted by: Mos_Ilie

Athlon II X4 640 (ADX640WFK42GR)

2011-10-07 16:37:50
Posted by: alexander

Athlon II X4 640 (ADX640WFK42GR) to phenom II X6 unknown model
asus M4A785TD-M EVO

Athlon II X4 640 (ADX640WFK42GR)

unloced 6cores

2011-11-13 14:53:22
Posted by: PaKO

Well, it worked! today unlocked the extra 2 cores on AMD Phenom II x4 960T and am now AMD Phenom II x6 1605T and all on board Gigabyte GA-MA770T-UD3P.


2011-12-08 01:53:35
Posted by: Ilian Saev

I unlocked Phenom II x4 960T to Phenom X6 1605 with asrock 870 Extreme 3 R2.0 .

CPU list

2011-12-28 12:45:38
Posted by: ABtech

The above list is CPUs with unlockable cores. The Athlon II X2 Regor has no unlockable cores and is not on the above list. The Athlon II X2 Regor does have 2MB L2 cache though.

unlock CPU core

2012-01-01 12:30:20
Posted by: TuZoli

The MSI 760GM-E51 (FX) motherboard have this feature to unlock CPU core.
Read here:
www.msi. com/ product/ mb/ 760GM-E51--FX-. html
remove the spaces


2012-01-02 05:53:38
Posted by: Valentin N

Can anyone make a list of which motherboard has this feature? Thanks

Response: I won't be able to make the list, but I can create simple database where everybody can post their unlocking results.

Phenom II X4 970 (also 975,965)

2012-01-15 09:02:45
Posted by: A Lurker

Black edition models:

965 @ 3.4 GHz
970 @ 3.5 GHz
975 @ 3.6 GHz

Response: There are no locked cores and/or L3 cache on these processors.


2012-01-16 03:25:20
Posted by: Valentin N

I forgot to say that this is a great article. I have posted in one of forums I am in. Thanks

unlocking cpu cores on AMD Phenom II

2012-01-17 01:48:41
Posted by: Dmitri

Can you unlock the AMD Phenom II X4 840?

Response: There are versions of Phenom II X4 840 processor, based on Deneb core. Those should have XXXX AC stepping code.

4 core thuban?

2012-02-05 14:35:05
Posted by: Michael29

Is this possible?
I have 4 core phenom 960T but CPU-Z says "Code name: Thuban"

4 core thuban?

Response: Yes, 960T has Thuban core, and has 2 CPU cores disabled.

my unlocking stats

2012-02-08 04:18:03
Posted by: System Builder

my results with core unlocking
of 5 x3 720 cpu that i tried 100% unlocked to black edition quad core.

of 3 960T that i tried one unlocked to six core.

of 2 x2 555 both unlocked to quad core.

of 5 amd sempron 130 and 140 models all unlocked to dual core.

wish i had better luck with the 960T
but overall i can not complain one bit.

your results may vary
good luck.

Athlon II x2 220

2012-02-14 14:44:31
Posted by: Andrarren

I have read a few threads that have said it is possible to unlock 2 more cores on this processor and a 6mb L3 cache, but have thus far had no luck in accomplishing this task. I have also not been able to locate any options in the BIOS to even overclock the processor.

Phenom II X4 960T

2012-02-17 18:00:19
Posted by: BroX

Successfully unlock one additional core on a Phenom II X4 960T. Unlocking all 6 resulted in a reboot while booting Linux.


2012-03-13 10:09:57
Posted by: Pro

The Sempron 145 turns into:

Athlon II x2 4450e

AMD Athlon II X3 @ phaenom X4 B60

2012-03-15 11:22:22
Posted by: Fistandantilus

ASUS m5a88m evo
AMD Athlon II X3 460 3,4Ghz rana @ phaenom X4 B60 propus
Stable work. Long live AMD

AMD Athlon II X3 @ phaenom X4 B60

Athlon x3 455 unlocked Successfully and stablily

2012-04-26 04:23:59
Posted by: Andy J

Thumbs up to AMD! i successfully unlocked my athlon x3 455 rana to a phenom x4 b55 and clocked it from 3.3ghz to 3.5ghz i know it can go higher but i kept it safe.

The motherboard that unlocked it was a ASRock n68c-s ucc

For Ģ62.30 its a bargin for a quad core thats capable of being clocked to 4.0 ghz i would even try it with a stock cooler lol

Phenom II X3 B73

2012-04-30 23:16:40
Posted by: Fraoch

You may want to add this to the chart, it unlocks to:

Phenom II X4 973

Well...theoretically. I tried it on my Biostar A880GU3 motherboard, it works from the BIOS almost all the time and *once* I got it to boot into the OS. However the OS hangs at boot most of the time and every once in a while the board will come up with "ACC Failed, press F2 to set BIOS to defaults".

So I guess I'm out of luck. Oh well.

Not so fast on my last comment...

2012-05-01 08:14:58
Posted by: Fraoch

ACC has several settings. I tried "Auto".

However I tried "Manual" which will allow you to overclock/underclock each core, a link on the web indicated the core might be stable if underclocked. The "hidden" core at 0% underclock/overclock wouldn't boot the OS. Neither would -2% or -4%. I did get into the OS at -6% but had a non-responsive pointer.

At -8% everything seems fine though. I'm testing all cores with cpuburn, no failures, so it looks like this is a winner. A -8% clock puts the hidden core at 2.576 GHz, not too shabby!

Not so fast on my last comment...

Athlon II 170u with Core #2 unlocked

2012-06-19 13:12:21
Posted by: igor.precep

Athlon II 170u with unlocked Core #2 on motherboard ASRock N68-VS3 UCC (via BIOS version P1.10 & P1.20 with UCC option in BIOS) now recognized as 2-core Athlon II X2 270u (by motherboard BIOS) or Athlon II X2 270 (by CPU-Z 1.60.1). Tested in all sort of applications for few days and stressed with Prime95 for few hours without single one problem. CPU is working stabile on 2x 2GHz without VCore raised up, VCore is left as it is in BIOS (Auto). Only problem I had with it is that motherboard sometimes only on first boot attempt recognize processor as it is: Athlon II 170u ...so I've turned off in BIOS options: Boot Guard and Cool'n'Quiet and problem mentioned above didn't happened again.

Athlon II 170u with Core #2 unlocked

AMD Athlon II X3 455 processor

2012-06-21 17:36:25
Posted by: kamotekid

I unlocked mine but in cpu-z it shows 801.98mhz...i believe this is the same issue as what "chaosmountain" posted above but not sure if it resolved the issue by disabling the Cool n' Quiet in the BIOS. it won't go pass 800MHz even in full load. can someone help? one more thing...core temp shows 80C when i loaded windows.

same as posted above

2012-06-21 18:25:53
Posted by: kamotekid

also, even if i ran prime95 at full, the clock speed didn't change..still @800MHz @ full load...you guys think that disabling the Cn'Q in the BIOS will help. has anyone resolved this kind of issue before? many thanks!

callisto core phenom

2012-07-15 05:16:38
Posted by: mikeym1a

This forum does not address the Callisto core Phenom.

Can they be unlocked? I am curious about the HDZ555, X2.

Response: There are multiple references on the page for the Phenom II X2s, including CPU-z screenshot of unlocked X2 555 processor.

it works :)

2012-08-29 17:15:46
Posted by: Daniel

Thanks for Fernando Arauco's comment. I have the same mainboard and after that one little switch, four cores were enabled in my Phenom II X2 550 (and recognized as Phenom II X4 B50).

Phenom II x4 840 has a L3 Cache

2012-10-12 18:25:57
Posted by: SilverWolf13

Unlocked my bios and i got a 6mb L3 cache Thanks a million for this thread

Phenom II x4 840 propus to denab

2012-10-13 12:32:59
Posted by: SilverWolf13

When i unlocked the propus cpu changed into a denab, and it opened up cores5, 6, 7, and 8, aswell as adding a 6mb L3 cache, over all im very happy with this thanks again, im also able to achieve a 3.6ghz oc from 3.2ghz with no major bios changes and 100% stable!


2012-10-13 20:43:00
Posted by: Malinko

Tried to unlock mine AMD phenom II 960t with gigabyte ga-970-d3 but no luck.After trying to do so system would not boot,got black screen and no bios message or anything,coolers were spinning and nothing else.I tried to clear Cmos and that didnt work either.Then I removed CPU from socket and placed it back and after that system booted.Was in panic for 10 min while mine computer was unable to start,but now I am happy that it works again.Wont try to unlock it again.

Athlon IIX2/Phenom IIX4 IMC

2012-11-09 00:14:28
Posted by: Nu2OCnCU

Hi. Noob here just getting into core unocking, etc. The information you've provided is GREAT,thanks!

My questions are: if an Athlon II X2 220 is unlocked "to" a Phenom II X4 920(925?), what's the IMC's max memory frequency? If it's a Deneb, shouldn't it have the same IMC as the Phenom?

Per AMD, the Athlon II X2's are limited/support to 2 DIMMs at 1066MHz or 4 DIMMs at 800MHz. The Phenom II's are at 1333MHz for 2 or 4 DIMMs.

Phenom II x2 560

2012-12-04 23:34:18
Posted by: JackAction

I bought a Phenom II x2 560 BE that unlocked to the Phenom II x4 B60, but windows wouldn't boot up. With the process of elimination I figured out that the 4th core was defective so it's still recognized as the x4 with 4th core disable and running stable at 3.3ghz stock 2 core settings. Thanks for the chip info, I noticed the AC on chip and knew asap that it was Deneb core. FYI - Biostar motherboard wouldn't unlock this chip at all, it's currently on a Gigabyte board.

Phenom II x4 650T unlock ~ Phenom II x6 1605T

2013-02-04 09:47:49
Posted by: stefanox

it's possible???? =)




Phenom II x4 650T unlock ~ Phenom II x6 1605T

Amd ATHLON 64 X2 5000+

2013-02-04 17:30:53
Posted by: TAZ

Can i unlock these ? i have info from this site only for amd x2 5000+ but nothing for 64 x2 5000+
CAA96 0746E AC

Response: Athlon 64 X2 processors cannot be unlocked.

athlon II x2 270

2013-02-22 04:46:58
Posted by: neotristram

Can i unlock my athlon II x2 270? i followed your instructions, but im just not e=seeing any diferrence? Thanks

Response: Athlon II X2 processors with 2 MB L2 cache cannot be unlocked. There is nothing to unlock there.


2013-03-07 13:40:59
Posted by: THomas

Hi, can I unlock this cpu to 6core? Is it Thuban core as well as adx640wfk42gr ?? Thanks for your help

Response: This processor does have any locked cores. If it has XXXXX AC stepping then you may be able to unlock L3 cache.


2013-04-03 13:57:01
Posted by: qweasd

can i unlock this?


Response: Athlon 64 X2 processors cannot be unlocked.


2013-05-06 00:01:46
Posted by: KG

my athlon 2 x3 455 is unlocked to a b55 and is clocked to 4ghz on air... the Spin Q cooler... 100% stable gaming for roughly a year... not bad for a $90(at time or purchase) cpu... although i know a i5 ivy bridge would be faster stock(next cpu is 3570k)

Addition to the list

2013-06-16 18:34:04
Posted by: space

I have a Phenom II X2 B55 and it unlocked to an Athlon II X4 555.
CPU-Z validation,

I will also add a screenshot with cpuz, coretemp, and HWmonitor.

Hope you guys can add this B series of processors to the compatibility list.

Addition to the list


2013-06-25 09:31:36
Posted by: Regor

can i unlock my athlon II X4 640 Propus 3.0GHz ADX640WFGMBOX?

Response: Only L3 cache can be unlocked on the Athlon II X4, and only if it's based on Deneb core (see the table).


2013-06-25 23:46:47
Posted by: Regor

this is my board anyway - asus m4n68t-m-le-v2

Phenom II X4 940

2013-09-12 21:30:47
Posted by: LarsBars

I actually did get this to work! I didn't think it was working, then I realized that mine is a Deneb core. The only extra features for my particular core is an extra 2MB of L3 Cache. Checked in task manager and sure enough, I now have 6MB L3!

Phenom II X4 940
Advanced clock calibration: Auto
Unleashing Mode: Enabled

Cache a must.

2013-09-14 23:22:33
Posted by: Mark

AMD dropped the ball by lowering it's cache level.

Athlon II x3 460 > Phenom II x4 B60 Propus

2014-01-01 14:54:41
Posted by: unlockerguy

So the mentioned athlon gets unlocked to phenom ii x4 B60 with no L3 cache. Sorry, no pic yet

Athlon IIx4 620

2014-04-17 22:33:08
Posted by: PHROZEN

Unlocked L3 cache. Worked great for a while but eventually my computer wouldn't boot. Through process of elimination I figured out the problem was the ACC which Unlocked the cache. My best guess is that it didn't pass quality specs but still worked, eventually wearing out. Still just as fast, especially with a SSD


2014-04-28 13:58:53
Posted by: Hunter

Bom o que eu quero saber é o Athlon II X2 270 tem nucleos para desbloquar? seria bom ele liberar mais 1 ou 2 nucleos...será que pode me dizer?

Last modified: 17 Oct 2013
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