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HD3870 & power saving

Discussion in 'AMD / ATI' started by durz, Jan 1, 2008.

  1. Cold Storm

    Cold Storm Battosai

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    when I place the fan speed to 100% it sounds the same... Even a Cosmos case won't damper the sound of the video card, it does to better extent... I just don't care for the leaf blower sound... its only going to be on when I game for a long period of time, or benching...
     
  2. Graogrim New Member

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    Don't worry about WoW. If you use RivaTuner, which seems to have monitors that work correctly for the HD3850, then you'll probably see the card's clock adjust up and down during gameplay depending on what load the card is being placed under.

    Bear in mind that WoW really and truly is not a very demanding game for video cards. It actually wants more of the CPU, and in most cases where you find your framerate visibly suffering below 60 fps it's due to CPU limitations. When the video card is sitting there waiting for more data from the CPU, it only makes sense for it to clock back down to its baseline.

    Paradoxically this means that the video card sees more GPU usage in scenes with less geometry rather than more. Aim the camera straight at the ground so that your framerate maxes out, give it a few seconds for the monitors to record, and then tab out and check to see how your clockrate is doing. Do not rely on the CCC clock monitor for this because when you tab out of WoW its rendering engine pauses, dropping the GPU's workload back to 0.
     
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  3. Geonerd New Member

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    Interesting thread. I really hope a software or bios fix surfaces.

    A little worried, I tested my Powercolor 3850/512/'extreme'/PCS.
    It appears to run at full 3d clock ALL the time! If Rivatuner's monitor is accurate, it never throttles down from 720 core, even when running a vanilla XP desktop.
    I'm not using RT or any other utility to set the clock to a specific speed.

    If true, this would strongly imply a bios level setting that might be patched.
    The alternative, a watchdog/'cop' chip on board, seems unlikely.

    Or perhaps it's something buried in the CCC bloat?
    I didn't install the Catalyst Software Suite.

    Cat 7.12, drivers only (7-12_xp32_dd_55811.exe)
    XP/sp2

    FWIW
     
  4. King Wookie

    King Wookie New Member

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    :toast:

    I'll try that when I'm finished modding the machine.

    My curiosity is aroused now. Anybody know someone from ATI who might know how this actually works?
     
  5. Oldjools New Member

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    Its something ATI need to address, heres what we are up against....

    [​IMG]

    Notice there are 3 power states, it sounds a great idea but from my own testing it seems that the boundary of these power modes is around 33 & 66% GPU load, what seems to have been overlooked is that no game runs at a constant GPU load in reality the load fluctuates wildly so depending on your game/system it could be going in & out of all 3. Now it gets much worse if you are playing an older title where you would expect nice high frame rates, instead the card slows itself down into 'light gaming' mode or worse 2D mode & runs rather badly. If like me you upgrade your system a bit at a time & your system is CPU limited you can get problems with new titles which should run fine with reduced resolution & or reduced quality settings but that puts you into a reduced GPU load situation & you can guess what happens next. Overclocking with Riva Tuner makes some people think it doesn't happen to them as that will lock the 2D clock at whatever you overclocked to so Riva Tuner wont show any downclocking, the same applies to the factory overclocked cards like Gecube/Powercolor. That does not stop Powerplay from being active.

    Powerplay has been around for a while on the Mobile Radeons as far as I'm aware on these its possible to disable it or set the mode to whatever you want, why this has not been done with the desktops is a mystery & why we have the Light gaming mode is beyond me as gamers want things as fast as possible all the time. I raised a support ticket with ATI & asked if it could in anyway be disabled & what about some powerplay settings in the CCC, this was the reply ...
    I have directed the feedback to the Catalyst Crew Team and the Feature Request Team.
    Currently there are no announced plans for the features you have requested or any workarounds to disable PowerPlay.

    Unless there are loads of 3800 customers raising support tickets or some bad press about this I cant see that position changing.

    This is the evidence I submitted to ATI, this is Crysis occasionally going through all 3 modes & could be the reason for the occasional stutter. http://www.jools2.ukfsn.org/Crysis.png
    Next is UT3, the start of this recording shows what happens if you stay in a very restricted (visually) area move outside then go back, the rest is just normal gameplay.
    http://www.jools2.ukfsn.org/UT3.png
    This ones a flight sim, my X1800XT runs this with ease at 60+ fps at 1600x1200 everything maxed the 3870 finds this too easy so it just stays downclocked with a very jerky 17-35fps, in contrast an 8800GT will give 100fps here.
    http://www.jools2.ukfsn.org/Condor.png

    I recently tried a bios with the same clocks & voltages in all modes but the result was unchanged but then its not certain just what Powerplay adjusts on the card anyway. I'm just hoping that with the number of related forum topics there are around now that ATI take notice & do something... if I'm gaming I want everything my gfx card can give me, thats what I bought it for.
     
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  6. Graogrim New Member

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    I'm not quite convinced this is an accurate characterization of what's happening. Think for a minute about some details of the explanation of PowerPlay's functionality. The embedded controller makes its decisions based on an evaluation of the contents of the command buffer. That suggests to me that if the GPU is clocking down, it's because the command buffer is either empty or nearly empty. I can easily envision a case where the GPU has completed a frame and vsync is enabled, causing the queue of pending operations to zero out long enough for the card to decide to downclock. Also, cases where data must be loaded or retrieved from the pagefile could easily trigger a downclock.

    What I'm saying here is that you're making the assumption that Powerplay is triggeringing hitches. But what if you have your causality mixed up and it's the hitches that are triggering Powerplay?

    That doesn't mean the issue isn't ATI's responsibility. There could be a driver bug leading to performance issues (like the framerate problem with cinematic playback in Crysis with pre-7.12 Catalyst), but that doesn't mean Powerplay is the cause.

    I've taken a look at your screenshots and I have a couple of questions. First, where is the evidence of use of "light gaming mode"? I see only direct state changes between low clock and full clock. Second, why are you using hacked drivers for this evaluation? They might provide superior performance in certain cases, but often trade off performance elsewhere or even introduce buggy behavior. Certainly in any discussion with ATI I'd suggest submitting results based upon official drivers.

    Now I'm not saying you're absolutely wrong. If you're having performance issues then clearly there's a problem somewhere. I'm just saying that maybe the problem is more complex than we know.
     
  7. Oldjools New Member

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    I did realize when I was doing my support ticket that those screens showed Omega drivers in use & I pointed out to ATI that they had been tried to see if there was any difference in performance with this issue between Omegas & official CAT drivers.(Omegas are well known to ATI ) Exactly the same happens regardless of drivers Omega & CAT 7.11, 7.12 & 8.01.

    What is the clockspeed of the light gaming mode? I have a feeling it may be the same as 2D mode, but also there is a step in the clockspeed when clocking up or down what is that... we dont really know what the full extent of the power saving features are. Whatever is going on people are reporting the same clockspeed switching in a variety of games & where GPU load is low performance is very poor which is the opposite of what you would expect.

    I have now heard that ATI are looking at this as the problem is quite widespread, when I have some news on that I will post it, hopefully that wont be too long.

    X1800XT going back in for the time being :(
     
    Last edited: Jan 19, 2008
  8. PashaM New Member

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    i dont bother with non of those tweaking tols, and i didn't know about it throtling back... i just installed the card and thats it. It playes Crysis and COD4 like a charm :)
     
  9. Oldjools New Member

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    Mine plays Crysis & COD4 fine & those games alone would not have had me looking at what was going on, in both I do get the occasional stutter but its not a big issue. What got me looking was a flight sim that ran great on my X1800XT but ran such a low frame rate with the 3870 that it was unplayable, the same seems to happen with MS FSX which is their latest sim & a lot of other titles. The biggest problems come with older games which should run flat out but dont run very well because the card responds to GPU load & decides to run slow. Heres a couple of threads (nothing to do with me) which discuss the same problem...
    http://forums.amd.com/game/messageview.cfm?catid=260&threadid=91209
    http://www.xtremesystems.org/forums/showthread.php?t=173203
    http://www.hardforum.com/showthread.php?p=1031950956#post1031950956

    It does seem that if your system is holding the card back a little then turning GFX options down a bit makes the problem much worse as its unloading the card & powerplay responds to GPU load which is the oposite to what you would normally expect from a GFX card. I think the issue is far more complex than most people believe, this is from the developer of powerstrip about setting clockspeeds with the 3800 series...

    Yes, I understand. But AMD has requested that PowerStrip use their API to read and write the maximum clock speed, and that's what we do.

    You can configure PowerStrip to set the clocks directly, even if no ATI driver is in use, but that's really not appropriate with contemporary GPUs because they run at variable clock speeds and voltages - with the 3870 the clocks are constantly and automatically changed based on GPU load and temp. At one time, GPUs ran at a single speed, from power up to power down. Then they ran at dual speeds - one speed in 2D, and another in 3D. Now they run at variable speeds.

    Long and short of it is you should use ATI's Overdrive to set the clocks exclusively. Otherwise you'll never know what you're running at, because of the multiple possible values that can be read.



    That makes me think these cards are being a bit too enthusiastic about changing speeds & voltages etc.
     
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  10. trog100 New Member

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    are we sure it isnt simply a vista desktop thing.. vista sometimes runs a semi 3d desktop.. no on wants their card cranking up to full speed just to runs fancy vista visuals.. ????

    i am using XP.. i cant reproduce this variable speed thing.. so is it a vista only thing.. ???

    trog
     
  11. niko084

    niko084

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    Thats odd if you are forcing your clock speeds for it to be still auto stepping down.... My 3870's didn't do that nor does my 3850..

    How are you sure its stepping down?
     
  12. Oldjools New Member

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    Running XP here.
     
  13. trog100 New Member

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    okay.. i tell a lie..i can reproduce "something".. this is running a year 2000 futuremark.. they used to be mad onion back then.. its 3dmark2000..

    its as near as i can get to an older game.. ignore the last portion to the right.. the rest is while running the benchmark..

    i see no sign of variable speeds (dynamic throttling) but it quite clearly drops back down to 2d speeds for parts of the benchmark.. the sawtooth type drops are each new sequence loading.. the bigger flat ones are 3d frames flying past but the card drops out to 2d mode..

    we are talking silly frame rates here.. over a thousand frames per second and in the hundreds even in when the card drops down to 2d speeds....

    the score of only 40000 reflects the fact the card was in 2d mode half the time.. 3dmark 2003 scores way more than that on my system..

    so i see the card dropping back to 2d mode when in theory it shouldnt.. i see no sign of fancy speeds in between..

    [​IMG]

    trog

    ps..rivatuner is simply being used to monitor whats happening.. speeds are set by the CCC..

    ps..2.. course even at a core speed of 300mhz the card should still manage older games without much of a problem..
     
    Last edited: Jan 22, 2008
  14. Oldjools New Member

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    That looks like the fan fix bios which has the clockspeed limit removed, also notice the step in the core clock as it clocks up or down, I cant work that one out but its the same with any bios with 300mhz 2D clock. I have tested that one & its a definite improvement over the the stock bios. This Powerplay issue is far more complex than just clocks & voltages, theres other things being adjusted that we don't know about. Heres an example, the tests are the same game with an identical test but different bios. The big question is why should GPU load be different? Performance with the Fan fix bios is better. I would have thought that the first test which is like a 300mhz gfx card should have a higher GPU load, its delivering an awful framerate & just cant get the job done fast enough. I'm no GFX card expert by a very long way but this seems to indicate that theres a general performance drop throughout the card with lower Powerplay states.. like theres a bottleneck before the GPU core.

    This is the stock clocks/bios test (this was done using the Omega drivers but official Cats produce identical results)

    [​IMG]

    This is the Fanfix bios test, notice how theres an increase in GPU load which probably triggers the higher core clock, unfortunately performance is still a long way below my X1800XT.

    [​IMG]

    This is the Powerplay states shown in bios by the Riva Tuner

    $0a00030000 PowerPlay state 0 : 777MHz/1126MHz/1.33V/boot
    $0a00030100 Performance level 1 : 777MHz/1126MHz/1.33V
    $0a00030200 Performance level 2 : 777MHz/1126MHz/1.33V
    $0a00030001 PowerPlay state 1 : 777MHz/1126MHz/1.24V/Overdrive
    $0a00030101 Performance level 1 : 777MHz/1126MHz/1.24V
    $0a00030201 Performance level 2 : 777MHz/1126MHz/1.33V
    $0a00030002 PowerPlay state 2 : 777MHz/1126MHz/1.24V
    $0a00030102 Performance level 1 : 777MHz/1126MHz/1.24V
    $0a00030202 Performance level 2 : 777MHz/1126MHz/1.33V
    $0a00030003 PowerPlay state 3 : 700MHz/1126MHz/1.33V/UVD
    $0a00030103 Performance level 1 : 700MHz/1126MHz/1.33V
    $0a00030203 Performance level 2 : 700MHz/1126MHz/1.33V

    Watching a few threads around the forums on this topic & ATI are getting support tickets raised about this issue along with card manufacturers but I don't think we will here anything until a fix has been done, ATI are not going to own up to a problem at this stage its not good for marketing.
     
    Last edited: Jan 27, 2008
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  15. tigger

    tigger I'm the only one

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    Does this problem afflict the 3850 as well?

    I wonder if this is hardwritten on the chip,can they fix it with a bios? And thats IF they will even admit its a problem.
     
  16. trog100 New Member

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    i did see a connection link between gpu use and the drop outs.. it could also be the system bottleneck causing it in some instances..

    what i dont see is any sign of controlled dynamic throttling.. when i run the same tests with supreme commader i see very spikey gpu usage.. but i put that down to cpu restrictions.. the card dosnt drop out of 3d speeds thow..

    there are three bios versions out there .. the original black screen at 862 one and two later ones.. version 071 and version 073..

    there might be some difference between 071 and 073.. i have stopped playing with the bios now.. the fanfix one does me..

    trog
     
  17. Oldjools New Member

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    Mines working well enough now to keep it in the comp, its great with things like COD4 but less demanding games its well below my old X1800XT in fps but it is now playable.. just. I gather the 3850 has similar problems, but with both it depends on what games you are playing. I submitted a review on Ebuyer UK mainly to mention the fan problems, all I did was advise people just to check with Riva Tuner the operation of the fan as some (like mine was) are stuck at about 23% & I mentioned the easy workaround using Riva Tuner... I submitted it but never saw it again, guess that proves that they dont like to have anything negative about what they sell :) I didn't mention the Powerplay problems either.

    Hoping this thread gets ATI's attention http://forums.amd.com/game/messageview.cfm?catid=260&threadid=91209
    This is another powerplay thread..
    http://www.xtremesystems.org/forums/showthread.php?t=173203
     
    Last edited: Jan 27, 2008

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