[Tested and Burned] ASUS Radeon HD 6950 DirectCU II Review (A card for Overclockers!)

ASUS HD 6950 DirectCU II review index

6 – ASUS HD 6950 DirectCU II Power Consumption and Overclocking

ASUS HD 6950 DirectCU II, FurMark 1.9.0

In this part, you will see why this HD 6950 DC2 made by ASUS is designed for massive overclocking 😉

For the power consumption and overclocking test, I used the upcoming FurMark 1.9.0 (still not released due to a little lack of time but it should be there shortly!). The graphics workload in the new FurMark 1.9.0 has been slightly increased, leading to more power consumption (few watts in more). But this extra graphics workload can make the difference with high overclocking settings.

The total power consumption of the testbed at idle with the HD 6950 DC2 is 110W.

ASUS HD 6950 DirectCU II, Geeks3D Testbed idle power consumption

The Radeon HD 6950 comes with a new power limiter technology called PowerTune:

ASUS HD 6950 DirectCU II, PowerTune

More details on PowerTune can be found in this test: [Tested] Radeon HD 6970 PowerTune Technology.

So the first thing to do to be sure that the HD 6950 is not limited by PowerTune (or limited to the minimum) is to set PowerTune to +20% in CCC.

With default settings (GPU @ 810MHz, Vcore @ 1.100V), the total power consumption of the testbed stressed by FurMark (FurMark settings: 1920×1080, fullscreen, Burn-in mode, dynamic background, no AA, no postfx) is 337W with a max GPU temperature of 79°C.
P = (337-110) * 0.9
P = 204 watts

where 0.9 is the PSU efficiency factor. For the Corsair AX1200 PSU, this factor is around 0.9 (see this article, there is a graph of the AX1200 efficiency).

204W is a correct value: the max TDP given by AMD is 200W (PowerTune +20%).

79°C is not a low temperature for a GPU but there is a reason: under FurMark burn-in test, the VGA cooler DirectCU II remains quiet! This is great:
there’s no perceptible difference between idle and full load.

Now let’s see the overclocking capabilities of this beast. Let’s see if the 8-pin power connector, replacing the standard 6-pin, brings enough power to push the card to the max.

Just a detail: I don’t know why, but I had some difficulties to properly overclock the HD 6950 DC2 with SmartDoctor alone. So I used a combination of SmartDoctor (for GPU voltage) and MSI Afterbuner (for GPU clock) to overclock the card.

The default GPU voltage (also called Vcore or VDDC) is 1.100V or 1100mV.
In the following lines, TPC is the reduced version of Total Power Consumption.

Let’s burn!

  • GPU core: 850MHz, Vcore: 1.100V, TPC: 345W, GPU temp: 81°C – Burn-in test: PASSED
  • GPU core: 880MHz, Vcore: 1.100V, TPC: 352W, GPU temp: 81°C – Burn-in test: PASSED
  • GPU core: 900MHz, Vcore: 1.100V, TPC: 354W, GPU temp: 82°C – Burn-in test: PASSED
  • GPU core: 950MHz, Vcore: 1.150V, TPC: 413W, GPU temp: 89°C – Burn-in test: PASSED

950MHz was the is GPU clock… actually it’s the max GPU clock written in the HD6950 BIOS. For the last burn-in test, I set the Vcore to 1.150V: it was for the fun, because with 1.100V, the HD 6950 was stable.

I have the good feeling that we can reach 1000MHz without problem with this card.

In the last burn-in test, the power consumption of the card alone is:
P = (413-110)*0.9 = 272W

An extra 72W compared to the TDP (200W). And absolutely no problem: the power circuitry of this HD 6950 is really well designed.

I submitted two 3DMark11 scores with GPU @ 950MHz:

ASUS HD 6950 DirectCU II, FurMark Approved

Here is a comparative table of the power consumption of the card ALONE (not the total power consumption of the system):

Power: 352W – EVGA GTX 580 SC (core: 880MHz, Vcore:1.082V) – OC settings
Power: 330W – ASUS ENGTX580 (core: 871MHz, Vcore:1.088V) – OC settings
Power: 324W – EVGA GTX 580 SC (core: 797MHz, Vcore:1.082V – default settings)
Power: 298W – ASUS Radeon HD 6950 (core: 840MHz, Vcore: 1.300V) – OC settings
Power: 290W – ASUS ENGTX580 (default settings)
Power: 276W – SAPPHIRE Radeon HD 6970 (core: 940MHz, Vcore: 1.175V) – OC settings
Power: 272W – ASUS Radeon HD 6950 DirectCU II (core: 950MHz, Vcore: 1.150V)
Power: 272W – EVGA GTX 480
Power: 260W – SAPPHIRE Radeon HD 6970 (core: 880MHz, Vcore: 1.175V)
Power: 225W – ASUS ENGTX560 Ti DirectCU II TOP (core: 900MHz, Vcore:1.025V)
Power: 220W – SAPPHIRE Radeon HD 6870 (core: 1000MHz, Vcore: 1.300V) – OC settings
Power: 204W – ASUS Radeon HD 6950 DirectCU II (core: 810MHz, Vcore: 1.100V)
Power: 197W – ASUS Radeon HD 6950 (core: 810MHz, Vcore: 1.100V)
Power: 185W – ATI Radeon HD 5870
Power: 155W – SAPPHIRE Radeon HD 6870 (core: 900MHz, Vcore: 1.175V)
Power: 147W – ASUS EAH6870
Power: 135W – MSI N460GTX Cyclone 768D5 OC

ASUS HD 6950 DirectCU II review index

33 thoughts on “[Tested and Burned] ASUS Radeon HD 6950 DirectCU II Review (A card for Overclockers!)”

  1. Pingback: ASUS GeForce GTX 580 DirectCU II Overclocked at 1519MHz!!! - 3D Tech News, Pixel Hacking, Data Visualization and 3D Programming - Geeks3D.com

  2. Psolord

    Great stuff.

    How about overclocking it with MSI Afterburner with unofficial overclocking enabled? Could it go past 950Mhz?

  3. JeGX

    I’ll try to post a short article on that topic but with “unofficial overclocking enabled”, I managed to reach 1030MHz under 3DMark11. Under FurMark, 950MHz seems to be the max stable clock speed, no matter the GPU voltage.

  4. JeGX Post Author

    @Em: yep you’re right, I didn’t see the picture and indeed the switch seems to be for display outputs instead of dual-BIOS. I will check with ASUS asap.

  5. JeGX Post Author

    Just sent an email right now! As soon as I get the answer, I update the article.

  6. Shadow NX

    Still no news on the switch?

    Could it be that Asus support rarely answers?

    Asked them a few things about this card also and after nearly 3 weeks i still dont have a answer.


  7. JeGX Post Author

    Ooops, I received the answer some days ago: according to ASUS, it’s a switch related to DVI linking, nothing to do with dual-BIOS.

  8. Najt

    asus are fucking fuckers with that switch!!!!! wrrrr…it coulde be one of te best cards! omg 🙁

  9. Derrick

    I have this card installed but for some reason when i open cpuz it doesnt show my clock speed or memory speed but it says I have -2048mb video memory…wtf.

  10. m03sizlak

    I bought this card because the review said the switch is a “DUAL BIOS SWITCH”. Now I find out THAT IT IS NOT. Thanks a lot buddy. You might wanna fix this review.

  11. Derrick

    By the way I just flashed(attempted) my Asus hd 6950 dc2 but it gave me a Blue screen hard crash……I only attempted to use winflash and ati rbe to just change the shaders to unlock 6970 status…FAILED…Stupidly I didnt have a flash drive so all i did was switch the little switch and IM fine…still normal bios though…But i havnt tried switching it back to the other one so I couldnt tell you if that worked…but as of now It is a dual bios switch.

  12. Derrick

    Ok i just found some outstanding results with this card people….everyone i just flashed it to a 6970 I have compiled a bios file if anyone would like a walkthru i will be glad to help them….This is now the best ati card (except 6990) right now….overclocked to 950 core 1350 mem and it is 1536 unified shaders 91.2GTexel/s I am extremly happy now….MY email is DerMoor@hotmail.com please no spam.

  13. m03sizlak

    Yeah I got mine clocked at 950/1350 as well. That silly BIOS trick isn’t worth possibly bricking my card. All the reviews show the unlock gains only 5% performance, whereas OC’ing gives the REAL gains. I do in fact love this card.

  14. Derrick

    Yea it is risky…but I still got the overclock and also higher shaders….Its not much of a gain between 5-20+ fps depends on the game and/or the benchmark utility. I use heaven dx11 demo cuz its pretty nice…also msi kombust or 3d mark vantage 1.1(free i think) idk….I am very pleased with this card to begin with but its pretty nice to prove people wrong about things…This card is a very nice tool for extreme gaming….once again thank you asus for a beast…cant wait until u make a 6990 dcii (with a modded bios switch) im all over it.

  15. m03sizlak

    Who are you proving wrong? The switch on this card is not a BIOS switch. On reference cards the switch toggles between a read-only BIOS and a writeable BIOS. This card has only 1 BIOS (writable). If you hose that BIOS the card is bricked.

  16. Derrick

    I’m talkin about the people that say this card isn’t unlockable and I tell u one thing if I turn my card on and let it load up I open gpuz it says I have 1536 unified shaders. Then if I turn my CPU off move the switch to the right and load it it does not. Maybe I have a reference board idk but I crashed my first bios loaded the second switch on and I was fine and was able to reflash my gpu again….then I could use the first switch again so I tried a different approach and it worked but if I flip the switch the other one is different. 1408 shaders….but IDC Im sorry for saying anything u win kid

  17. Em

    The card has both BIOS chips present… to verify, at the right of the South-Eastern GPU screw on the back of the card with the PCIe slot down, there is a horizontally placed/soldered chip… that’s the 2nd BIOS not present on cards without the switch.

    So the article is right but might have been by mistake, and ASUS kept quiet for commercial reasons, but you might hear about it if you bump into the support team when and if needed.

  18. Derrick

    Thank you em…He is correct Asus keeps things underwraps…Hell if everyone knew this there could be problems with Asus stealing everybodies business lol THANK YOU ASUS what a badass card..ROAR

  19. Garth

    I have been working on unlocking this card with Derrick today and after numerous bad bios attempts (I got a little too agressive on bios edits) and resets I can say without a doubt that the switch is for the DUAL BIOS as both Derrick and Em suggested. So far I have had the best luck backing up the original bios and then using the Radeon Bios Editor to unlock the shaders. I am showing 1536 shaders in GPU-Z and after some overclocking this thing is smoking fast!

  20. Pingback: Cercasi informazioni Asus Radeon HD6950 DirectCU II - Forum di Tom's Hardware

  21. Derrick

    Well today Garth had another breakthru and finally proved the fact that we can flash this card to a ASUS hd 6970 dcuii with the increased stock voltage to 1.175 which has allowed me to clock my card to 1015/1425. Have only ran haven dx11 benchmark which showed very little artifacts with a little tweaking I’m sure this can be resolved overall the flash was a success and everything looks ok. Temps didn’t really increase from what I can see…crossing fingers that the VRAM can keep up.

  22. Sven

    Can 2 ASUS HD 6950 DirectCU II (Crossfire) be installed on P8P67 Deluxe? Or will the 3-slot height VGA cooler be a problem?

  23. Derrick

    Well I am back I finally received my NEW hd 6950 dcuii RMA lol….I got very aggressive with this card and flashed from the 6970 bios garth gave me to a voltage modified 6950 bios which ended up bricking my card….Sadly before I figured out how to fix this card by pci flashing I RMA it cuz both bios switches were messed up because of the bad flash lol….WEll Asus Is spectacular with their customer service and made everything alllll better with a brand new in box Hd 6950 DCUII. So I am going to hold off on flashing with 6970 and see how I perform stock for a while…Hell I am even too scared now to even overclock higher than the stock 810 right now. Anyone have this card at 950/1350 nonunlocked runnin at this speed for a while. And if so is there any signs of wear and tear. thanks.

  24. Bluepanther

    Hey guys,

    I have the HD6950 DCU II 2GB. I’ve tried quite a few methods in order to unlock the shaders – so far havent had any luck.

    How have you guys unlocked your cards? I’ve tried enabling the shaders using RBE and then Winflashing. Also tried to flash with the HD6970 DCU II. GPUz still reports 1408 shaders.

    Any help would be much appreciated.


  25. PsYch0

    I’ve clocked mine HD5830 up to 980/5000MHz/1.125V
    Awesome card for clockers with knowledge 🙂

  26. Derrick

    Well I am still receiving emails regarding unlocking this card….as stated above I did unlock it but also eventually ruined my card. I RMA it to asus and luckily they replaced and shipped a new one for free…I noticed right off the back as soon as I installed this new card it performed better than my original card did at its stock state. So I figured why not try it again. Well I have tried every method I was able to do before and am completely unsucessful. I think I as well as a few others were lucky enough to buy cherry picked dcII cards. I wish i could be 100 percent certain but I couldnt use the bios garth and I compiled because I had to do a fresh install of windows and had no recovery available. So I really think the best way to get your money outta this card is to OVERCLOCK ONLY….I now use smartdoctor to control my voltage since afterburner does not allow this card to change volts..1.175 and then I OC’ed to 900/1300 because for some reason anything higher and it crashes but I dont think its a heat thing but who knows.

  27. Nick

    Can i crossfire the asus 2gb 6950 direct cu2 with the first generation asus 2gb 6950 on a 750w psu……no overclocks…just standard settings?

  28. Anthony

    Not sure if it has been mentioned but this article has a few errors. That is not a dual bios switch, it’s a dual lane DVI switch which assigns some bandwidth from one of the HDMIs to DVI so you can run beyond 1920 x 1200 on that port (which leaves hdmi1 disabled).

    This card has no dual bios switch so reflash at your peril!

  29. PESolution

    to unlock the bios on this card – u need to use RBE.

    Download ur original bios through RBA, go to the furthest tab to the right and click the unlock shaders / 6970 shaders option.

    DO NOT change anything else or you will blue screen on reboot.

    Using a premodified reference bios to flash this card doesnt work.

    Hope this helps,




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