Why do desktops GPUs lack even the most basic power management features?

Discussion in '3D Hardware, Software & Output Devices' started by corduroygt, Aug 24, 2010.

  1. corduroygt

    Banned

    Joined:
    Nov 26, 2008
    Messages:
    1,390
    Likes Received:
    0
    How hard is it to prevent the discrete card from powering up when you don't want to use it? Currently, the only way is to physically remove it. A solution that just requires a reboot could be easily implemented by a motherboard manufacturer by just not sending power to that card. A more sophisticated solution that enables switching on the fly like Nvidia Optimus on desktops should also be impelemented by Ati/Nvidia. Why can't I use my 890 northbridge gpu for all desktop tasks while only powering the discrete card(s) when 3D is needed? How hard is this to implement?
     
  2. homerdog

    homerdog donator of the year
    Legend Veteran Subscriber

    Joined:
    Jul 25, 2008
    Messages:
    6,294
    Likes Received:
    1,075
    Location:
    still camping with a mauler
    Where would you plug in the monitor?
     
  3. Dave Baumann

    Dave Baumann Gamerscore Wh...
    Moderator Legend

    Joined:
    Jan 29, 2002
    Messages:
    14,090
    Likes Received:
    694
    Location:
    O Canada!
    On a desktop the bus is designed to always be alive and turning off the power to the GPU effectively hot plugs/unplugs the device on the bus. Not great without a ecosystem to do it. It is achievable, but systems need to be designed for it; notebooks have the luxury of the specific GPU being designed into the system and features like this being design and qualified specifically for those components but desktop qualification needs to ensure that features work on a plethora of platforms.

    Secondly, on a notebook the VBIOS is part of the system BIOS, so it is always loaded even in a switchable graphics system. On a desktop the VBIOS is on the graphics card and would need to be loaded everytime you power the device off and then back on again, which causes a delay reactivating the device.
     
  4. orangpelupa

    orangpelupa Elite Bug Hunter
    Legend Veteran

    Joined:
    Oct 14, 2008
    Messages:
    9,641
    Likes Received:
    2,734
    hmm maybe ATi PowerPlay for desktop?

    on laptop it will downclock the gpu and ram clock to save battery. Currently i usually underclock on PC using ATi overdrive (to make the fan very quiete), but its manual.

    it will be great if it can detect game being played and go fullspeed. back underclock when exit game.
     
  5. no-X

    Veteran

    Joined:
    May 28, 2005
    Messages:
    2,407
    Likes Received:
    416
    Does it make sense? Are there any reviews comparing optimus system with standard system equipped by a GPU with good power managemenet features?

    At the time of optimus launch I checked some reviews of mainstream laptops (I skipped high-end models and low-end atom-based systems, too). 2D power drain was very comparable independently on the GPU...

    Code:
    Compaq Presario CQ61 - 315EC (Intel T4400 + Intel GMA 4500 MHD): 23W
    HP ProBook 6545b (AMD M600 + ATi HD4200): 17W
    ASUS M60J (Intel i7 820QM + NVIDIA GT240M): 22W
    Lenovo IdeaPad Y550 (Intel P7450 + NVIDIA G240M): 20W
    Lenovo ThinkPad SL410 (Intel P7570 + ATi HD4500): 17W
    Lenovo ThinkPad SL510 (Intel T6670 + Intel GMA 4500 MHD): 18W
    Why to implement such complicated solution, if the chipset-integrated GPU has nearly identical power drain as the "discrete" one?
     
  6. Malo

    Malo Yak Mechanicum
    Legend Veteran Subscriber

    Joined:
    Feb 9, 2002
    Messages:
    8,520
    Likes Received:
    5,001
    Location:
    Pennsylvania
    To what end? Power consumption? On normal desktop mode the 5000 series use very little power already downclocking the GPU and RAM far below peak levels.
     
  7. corduroygt

    Banned

    Joined:
    Nov 26, 2008
    Messages:
    1,390
    Likes Received:
    0
    What's your definition of very little power, as it still seems to be at least 30W, whereas an IGP will consume 10W or less...
     
  8. AlphaWolf

    AlphaWolf Specious Misanthrope
    Legend

    Joined:
    May 28, 2003
    Messages:
    9,336
    Likes Received:
    1,531
    Location:
    Treading Water
    At least 30? Where did you pull that number from? The 5870 uses more like 15 on the desktop.
     
  9. Malo

    Malo Yak Mechanicum
    Legend Veteran Subscriber

    Joined:
    Feb 9, 2002
    Messages:
    8,520
    Likes Received:
    5,001
    Location:
    Pennsylvania
    The 5770 is rated at 18w idle.
     
  10. corduroygt

    Banned

    Joined:
    Nov 26, 2008
    Messages:
    1,390
    Likes Received:
    0
    The difference between 3.2W vs. 14W is a lot, and that's only a 5770, (5870 will be more) not to mention the excessive consumption during HD video. It'd help If I could use something with the footprint of a G210/5450 at all times while only using a 5870 during gaming....
     
  11. Davros

    Legend

    Joined:
    Jun 7, 2004
    Messages:
    17,186
    Likes Received:
    4,574
    even worse if you use a nv card for physx its always running even when your not in a game
     
  12. AlphaWolf

    AlphaWolf Specious Misanthrope
    Legend

    Joined:
    May 28, 2003
    Messages:
    9,336
    Likes Received:
    1,531
    Location:
    Treading Water
    Yep the 5870 is more. But not much more.

    If you had to pay $10 up front for the extra chip to save you 12 watts. It's going to take you ~6000 hours to pay for it.
     
  13. corduroygt

    Banned

    Joined:
    Nov 26, 2008
    Messages:
    1,390
    Likes Received:
    0
    Why would I have to pay up for it to begin with? AMD could integrate an optimus-like solution in their IGP's, to have it as a selling point for their platform and cpus for example. If you're getting a radeon, get an AMD cpu/motherboard and we'll turn off that extra video card when you're not using it...
     
  14. AlphaWolf

    AlphaWolf Specious Misanthrope
    Legend

    Joined:
    May 28, 2003
    Messages:
    9,336
    Likes Received:
    1,531
    Location:
    Treading Water
    Building it in doesn't make it free and it wouldn't be a selling point for me if it cost $5 extra.
     
  15. mczak

    Veteran

    Joined:
    Oct 24, 2002
    Messages:
    3,021
    Likes Received:
    119
    10W more isn't really a whole lot. Dim your backlight a bit and that will save a similar amount of power...
    Really, I can't see Optimus-like solutions on the desktop anytime soon.
    At least nowadays graphic cards have quite a few power saving features which didn't exist until quite recently on desktop cards, even though the asics would have supported some (and those features were enabled in the mobile parts). Lower 2d clocks (with lower voltage), clock gating often weren't enabled - I think even for cards like 8800GTX that stuff was often (depending on card and maybe driver revision) disabled. That's not to say it couldn't get better - newest addition is lowering voltage for gddr5 memory when downclocked, so far a GTX460 exclusive on the desktop side.
     
  16. mito

    mito beyond noob
    Veteran

    Joined:
    Jun 16, 2004
    Messages:
    1,392
    Likes Received:
    10
    Location:
    Feindesland
    ok, here's my question.

    How do I disable my second GTX 280 in my SLI system?
    I don't want it to draw power when I'm not playing.

    By simply disabling SLI, will the second card shut down?

    Thanks.
     
  17. Davros

    Legend

    Joined:
    Jun 7, 2004
    Messages:
    17,186
    Likes Received:
    4,574
    Powervr managed it
     
  18. swaaye

    swaaye Entirely Suboptimal
    Legend

    Joined:
    Mar 15, 2003
    Messages:
    8,838
    Likes Received:
    894
    Location:
    WI, USA
    Check out some of the numbers here. There are some frugal chips out there, just not usually at the high-end.
    http://www.tomshardware.com/reviews/geforce-radeon-power,2122-6.html

    I remember that somewhere around the X800 that ATI added clock gating to the desktop. It was in the Mobility Radeons earlier though. The thing is that adding 10W doesn't really mean much to a desktop PC, but in notebooks it means a whole lot for battery life and that little bit of extra heat that's very tough to deal with.
     
  19. Blazkowicz

    Legend Veteran

    Joined:
    Dec 24, 2004
    Messages:
    5,607
    Likes Received:
    256
    there can also be a multi-monitor scenario where the second graphics card (primary being either integrated or discrete) could be switched off. so you third screen gets switched off in the process as well.

    it would shave a few watts in a mainly 2D/low intensity 3D workstation, or some more in a surround gaming setting.
     
Loading...

Share This Page

  • About Us

    Beyond3D has been around for over a decade and prides itself on being the best place on the web for in-depth, technically-driven discussion and analysis of 3D graphics hardware. If you love pixels and transistors, you've come to the right place!

    Beyond3D is proudly published by GPU Tools Ltd.
Loading...