HD 6950 2GB Unlocked Overclocking

Discussion in 'Videocards - AMD Radeon' started by MrBox, Apr 20, 2011.

  1. MrBox

    MrBox Guest

    I've been experimenting with 6950's for a few months now, and I've come to the conclusion that they are simply amazing.

    I'm using a Diamond 6950 2GB reference card at the moment for overclocking, and it's been truly exceptional. I have been able to push this particular card to 1Ghz with the stock reference cooler and it hasn't gone past 57c while running normal benchmarks & games.

    Here are the settings I'm currently testing:

    Unlocked shaders on modified 6950 bios.
    Memory timings un-altered
    Current Voltage: 1100mV
    Max Voltage Tested: 1175mV
    Core @ 1100mV = 1000Mhz
    Memory @ 1100mV = 1350 Mhz
    Fan is on a custom profile. It hasn't reached past 50% as the temps haven't gone past 57-59 max.
    OCCT has reported 0 errors
    I do not use furmark/kombustor anymore out of fear. I killed a 6950 by putting too much voltage into it I think. Not sure exactly what caused it, but it started permanently artifacting after I pushed it way too hard.

    The performance difference between 980Mhz and 1Ghz on the core is very small. I've been able to squeeze a few extra numbers out of it but in my opinion it's pointless. The best settings I've come up with are:

    1100mv
    940 Core
    1350 Memory

    These oc settings are great as I don't need to give it any extra juice, and I can run the fan lower and still get nearly the same performance as 980Mhz+

    I'm going to run both cards @ 940Mhz now and do some testing in crossfire with eyefinity @ 5760x1080. Will post benches when I have some free time later this week maybe.

    Anyone else have a similar experience or any tips with their 6950's?

    I love these cards. Also keep in mind I have a gtx 570 and had a 470 before it. I was using 570 in SLI but sold one of them to pay for an extra 6950 after I realized how much I love them. The 570's were equally awesome but for some reason I just like the amd cards better.
     
  2. Plug2k

    Plug2k Ancient Guru

    Messages:
    1,540
    Likes Received:
    23
    GPU:
    3090
    [​IMG]

    Your right about that phenomenal cards
    my 24/7 clocks ;)

    Running Asus 6950 OC+ 2gb Cards Unlocked and flashed with ATI 6970 bios then overclocked :)

    ATI have really done something this time to there cards they dont freeze up under furmark anymore and they hardly ever break a sweat, running the clocks above i can furmark for over a hour and not hit over 72c

    :)

    Word of advice though run the fan higher my top cards temps are about 6c higher than the bottom card so if my top card maxes out at 72c the bottom is around 66c

    great cards though and they are not bottle necked anymore at al under tessellation :)
     
  3. MrBox

    MrBox Guest

    When I get them back crossfired later I will definitely use a higher speed fan profile. I was testing it in single mode, and not breaking 57c at full load. I also have a lot of air flowing through the case, and I keep my house at 68 degrees Fahrenheit.

    I love these little monsters. They are about the same as my 570, but for some reason the AMD cards are just way more fun to play with.
     
  4. velocityx

    velocityx Master Guru

    Messages:
    310
    Likes Received:
    0
    GPU:
    EVGA 1080 Ti FE - EK FCB
    I have to say im quite unimpressed with your OC here. the reason why you don't see performance gain is because your memory is low. The difference between 940 core and 1k is marginal until you clock your memory higher. When you do that it starts to fly off.

    I reached 940 stable with 1.1v on the core. My memory clocks at 1470mhz on stock voltage no change there from bios defaults. The thing is, I saw very marginal differences in performance while going from 940 to 990 when my memory was clocked at 1400mhz. I realized that theres something wrong so I started going up with my memory and then it took off like crazy. I didn't try going higher with my memory and I settled at 960 core with 1.175v ( I think since the chip is a 6970 anyway it wouldnt mind the voltage) and 1470memory which is surprising for me without voltage increase. custom fan profile in AB takes care of temps not going over 68C and 44on Vregs. Right now I feel like you 940 would be much better off with 1400 on memory.

    Did you try see how far the memory goes without voltage incr?
     

  5. MrBox

    MrBox Guest

    I actually tested it with much higher memory clocks, and I didn't see any real gains in performance. I have tried 1375/1400/1425/1450/1475 with several different voltages and didn't really see any serious performance increase. That's why I went back to the lowest memory clock that maintained the same performance.

    I'm sorry you're unimpressed with my experiences. :(

    *edit: I just ran a couple benches real quick with mem @ 1400 and 1450 and I didn't get a single extra point, and in one case I actually got a little bit less.
     
    Last edited by a moderator: Apr 20, 2011
  6. Mr.Joe

    Mr.Joe Master Guru

    Messages:
    287
    Likes Received:
    0
    GPU:
    670DC2-1333/3915-EK~H20
    say how do you change your vram voltage, other than flashing to a 6970?
     
  7. velocityx

    velocityx Master Guru

    Messages:
    310
    Likes Received:
    0
    GPU:
    EVGA 1080 Ti FE - EK FCB
    thats really strange. but in battlefield bad company 2 multiplayer I went from 44 frames in the heat of oasis battle to 70-80 frames per second between 1400/1470 and crysis 2 fps stabilzed higher as well. 3d Mark11 reported 170 more points. overall improvement.

    I wonder whats the deciding factor here.
     
  8. MrBox

    MrBox Guest

    I just noticed something strange though. When I re-enabled my 3.8Ghz overclock on the i7 950 i noticed frames went up with higher memory clock a bit.

    I don't know how a CPU bottle neck would affect the VRAM, maybe it wasn't sending info fast enough.

    I'm going to take some time tonight and do benchmarks on stock CPU, and OC at 3.2Ghz and 3.8 Ghz with the different mem clocks. I'll post some results when I've finished to see if it makes a big difference.
     
  9. velocityx

    velocityx Master Guru

    Messages:
    310
    Likes Received:
    0
    GPU:
    EVGA 1080 Ti FE - EK FCB
    so how did it go MrBox? any interesting results?
     
  10. davetheshrew

    davetheshrew Ancient Guru

    Messages:
    4,089
    Likes Received:
    1
    GPU:
    some green some red
    vram boosts frames with these cards , 1020-1475 rock solid here no problems and no throttling , best tip for these cards is WC or a better air cooler, that is all.

    p.s run metro bench or crysis bench looped for around 10 mins and to finish loop test 4 of 3dmark11 for 10 mins also, trust me your card will be unstable at such low volts at high clocks, most cards wont survive, will yours? :nerd:
     
    Last edited: Apr 22, 2011

  11. velocityx

    velocityx Master Guru

    Messages:
    310
    Likes Received:
    0
    GPU:
    EVGA 1080 Ti FE - EK FCB
    well

    I've had this overclock for quite some time now, and I really want to challenge your opinion, unfortunately I dont have any of these benchmarks, I have 3d mark but a basic one not the full one. I dont have metro or crysis right now to test. and im not going to fire up furmark. 3d mark basic is stable and all games play fine for hours.

    so I'm not really so sure about your statement
     
  12. davetheshrew

    davetheshrew Ancient Guru

    Messages:
    4,089
    Likes Received:
    1
    GPU:
    some green some red
    furmark is crap dont use it its not reliable for stability its only reliable for extreme non game temps, blunt but true.

    Test4 of 3dmark11 is a seriously demanding bench and gives the gpu a damn good pounding as far as games go, certain levels of metro do aswell, crysis is a given, if its not stable in crysis then no hope in hell of it being stable for many hours in pretty much any game with all bells and whistles/full res etc. Problem with Crysis tho is you need around 30 loops to find error sometimes, the other tests I mentioned will show in 10 mins...

    the space test in vantage is free, was it called new calico? thats fairly demanding-ish..loop that for 10 runs.

    Mate Im offering advice you can challenge me but I think I will just end up letting you rage while I chill knowing my clocks dont throttle and my temps are sweet for days of gaming not minutes ;)

    :nerd:

    Some benchers allow a margin of error and will let a bench run through to show off their high scores, I personally am a gamer and bencher, I know my bench scores and limits well, I know my game clocks far better :biggun:

    cool your card and lets have a showdown:newb: Im 22nd in the world for this card and quite possibly first for air, I accept your challenge of opinion and further a challenge of a duel :):vader:

    when you lose remember to thank me for releasing the first info's on unlocking your card, it was in an article on custom pc and pc format in the uk last month, am I proud for having the guts to potentially brick my card on 26th-ish dec? oh yes I am :)
     
    Last edited: Apr 23, 2011
  13. MrBox

    MrBox Guest

    Still haven't had time to go through all of that yet. I WILL get around to it this weekend though, I promise. Too busy running my business ATM.
     
  14. MrBox

    MrBox Guest

    I've run vantage, 3dmark11, heaven 2.5, and OCCT especially for 5 hours the other night. I haven't had a single issue with stability. This particular card has run amazingly well on low voltage compared to the other 6950's I've had. The one that I RMA'd didn't do so well so I had to pump the voltage up and it ended up biting the dust. This one in particular is something special.

    To Dave: I hope you aren't challenging ME to a duel. I have no interest in that, and I'm sure your card runs extremely well. They are amazing to say the least. I am by no means an "extreme" overclocker though. I'm just interested in seeing how far other people have pushed these cards.

    I do think, however that you seem a little agitated. I hope I haven't offended you in some way, sir.
     
    Last edited by a moderator: Apr 23, 2011
  15. DementeD

    DementeD Master Guru

    Messages:
    851
    Likes Received:
    0
    GPU:
    AMD "6970" 1000/1500
    i just wanna see the 1000core/ 1.1v tests..cause i dont see any proof of that and honestly sounds a little too good to be true. so if you dont mind and dont get offended thats just incredible..but yea post some benching testing on something demanding of those clocks please :)
     

  16. velocityx

    velocityx Master Guru

    Messages:
    310
    Likes Received:
    0
    GPU:
    EVGA 1080 Ti FE - EK FCB
    wait cause I got lost a bit, dave, demented,

    my gfx rig is clocked at 960 1.175 and stock vmem at 1470mhz. Who said about 1k core at 1.1?

    why are you offering advice? where is that advice because from what I see you're doubting that it's stable and not offering me advice. From my cards perspective, putting 1.3v on core for a silly 1k is just pointless. Or I just have a good card here. I consider it stable I game everyday, crysis 2, shift 2, bfbc2, all stable I tested 3dmark 11 a couple of times nothing crashed, heaven 2.1 works fine (2.5 doesnt work for me for some reason, tells me about some dlls which I had no time to research). so, yea, you think my card in the long run isn't stable, and I say it is. I will do more benching, however I won't overclock the card more than it is now as I'm not really a fan of pushin 1.3v on the core :]
     
  17. davetheshrew

    davetheshrew Ancient Guru

    Messages:
    4,089
    Likes Received:
    1
    GPU:
    some green some red
    haha mr box no not you the other guy who said hed like to challenge my opinion ;) but still show benchies proving 1000 core at 1100mv, thats crazy man.

    volocityx: matey if you cant see the advice Ive given you in my last few posts you are blind son, you know how to OC right and I dont need to give you advice on OC right? The 'advice I gave is what benches to run, like you mentioning furmark and me shooting it down, if you cant take that on board well you know what to do, enjoy your card, hope it really does last the distance at silly low volts, I have my doubts it will last but who cares huh its only money :)
     
    Last edited: Apr 23, 2011
  18. DementeD

    DementeD Master Guru

    Messages:
    851
    Likes Received:
    0
    GPU:
    AMD "6970" 1000/1500
    the 1.1v is mrbox OP said 1100mv(1.1v) = 1000mhz core and THAT i want to see..
    960 at 1.175 yes is very doable i had mine at 950 1.175 no problems(im pretty anal about my clocks ie i want them to be something like 950 975 1000 1050 etc..like i can run 1035 core at 1.3 volt but i like 1000core look better hehe so i run that ..weird/stupid i know but thats just me :) i need to lower volts though just cause i know i can.
     
  19. velocityx

    velocityx Master Guru

    Messages:
    310
    Likes Received:
    0
    GPU:
    EVGA 1080 Ti FE - EK FCB
    dave I really dont get why you're so uptight. I said I wont use furmark annnnyyyway

    you mention something about cards not lasting. so you say low voltage on the card is unsafe for the card? or do you mean that I will bsod at one point or another. I will try to do the benchmarks, and see how it goes.

    don't need to be so overly ghetto.
     
  20. loneknives

    loneknives Master Guru

    Messages:
    229
    Likes Received:
    0
    GPU:
    Galaxy gtx 670 GC
    man i like to see 1.1v at 1000 core benchmark :)
    in order for me to get 1000core i need 1.26v stable
     

Share This Page