Power and Power Management

Power is a major concern of many tech companies going forward, and just adding features "because we can" isn't the modus operandi anymore. Now it's cool (pardon the pun) to focus on power management, performance per watt, and similar metrics. To that end, NVIDIA has beat their GT200 into such submission that it's 2D power consumption can reach as low as 25W. As we will show below, this can have a very positive impact on idle power for a very powerful bit of hardware.

These enhancements aren't breakthorugh technologies: NVIDIA is just using clock gating and dynamic voltage and clock speed adjustment to achieve these savings. There is hardware on the GPU to monitor utilization and automatically set the clock speeds to different performance modes (either off for hybrid power, 2D/idle, HD video, or 3D/performance). Mode changes can be done on the millisecond level. This is very similar to what AMD has already implemented.

With increasing transistor count and huge GPU sizes with lots of memory, power isn't something that can stay low all the time. Eventually the hardware will actually have to do something and then voltages will rise, clock speed will increase, and power will be converted into dissapated heat and frames per second. And it is hard to say what is more impressive, the power saving features at idle, or the power draw at load.

There is an in between stage for HD video playback that runs at about 32W, and it is good to see some attention payed to this issue specifically. This bodes well for mobile chips based off of the GT200 design, but in the desktop this isn't as mission critical. Yes reducing power (and thus what I have to pay my power company) is a good thing, but plugging a card like this into your computer is like driving an exotic car: if you want the experience you've got to pay for the gas.

Idle Power 

Idle power so low is definitely nice to see. Having high end cards idle near midrange solutions from previous generations is a step in the right direction.

Load Power 

But as soon as we open up the throttle, that power miser is out the door and joules start flooding in by the bucket.

Cooling NVIDIA's hottest card isn't easy and you can definitely hear the beast moving air.  At idle, the GPU is as quiet as any other high-end NVIDIA GPU.  Under load, as the GTX 280 heats up the fan spins faster and moves much more air, which quickly becomes audible. It's not GeForce FX annoying, but it's not as quiet as other high-end NVIDIA GPUs; then again, there are 1.4 billion transistors switching in there.  If you have a silent PC, the GTX 280 will definitely un-silence it and put out enough heat to make the rest of your fans work harder.  If you're used to a GeForce 8800 GTX, GTS or GT, the noise will bother you.  The problem is that returning to idle from gaming for a couple of hours results in a fan that doesn't want to spin down as low as when you first turned your machine on.  

While it's impressive that NVIDIA built this chip on a 65nm process, it desperately needs to move to 55nm.

GT200 vs. G80: A Clock for Clock Comparison The Test
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  • tkrushing - Wednesday, June 18, 2008 - link

    Say what you want about this guy but this is partially true which is why AMD/ATI is in the position they have been. They are slowly climbing out of that hole they've been in though. Would have been nice to see 4870x2 hit the market first. As we know competition = less prices for everyone! Reply
  • hk690 - Tuesday, June 17, 2008 - link



    I would love to kick you hard in the face, breaking it. Then I'd cut your stomach open with a chainsaw, exposing your intestines. Then I'd cut your windpipe in two with a boxcutter. Then I'd tie you to the back of a pickup truck, and drag you, until your useless fucking corpse was torn to a million fucking useless, bloody, and gory pieces.

    Hopefully you'll get what's coming to you. Fucking bitch


    http://www.youtube.com/watch?v=XNAFUpDTy3M">http://www.youtube.com/watch?v=XNAFUpDTy3M

    I wish you a truly painful, bloody, gory and agonizing death, cunt
    Reply
  • 7Enigma - Wednesday, June 18, 2008 - link

    Anand, I'm all for free speech and such, but this guy is going a bit far. I read these articles at work frequently and once the dreaded C-word is used I'm paranoid I'm being watched. Reply
  • Mr Roboto - Thursday, June 19, 2008 - link

    I thought those comments would be deleted already. I'm sure no one cares if they are. I don't know what that person is so mad about . Reply
  • hk690 - Tuesday, June 17, 2008 - link


    Die painfully okay? Prefearbly by getting crushed to death in a garbage compactor, by getting your face cut to ribbons with a pocketknife, your head cracked open with a baseball bat, your stomach sliced open and your entrails spilled out, and your eyeballs ripped out of their sockets. Fucking bitch
    Reply
  • Mr Roboto - Wednesday, June 18, 2008 - link

    Ouch.. Looks like you hit a nerve with AMD\ATI's marketing team! Reply
  • bobsmith1492 - Monday, June 16, 2008 - link

    The main benefit from the 280 is the reduced power at idle! If I read the graph right, at idle the 9800 takes ~150W more than the 280 while at idle. Since that's where computers spend the majority of their time, depending on how much you game, that can be a significant cost. Reply
  • kilkennycat - Monday, June 16, 2008 - link

    Maybe you should look at the GT200 series from the point of view of nvidia's GPGPU customers - the academic researchers, technology companies requiring fast number-cruching available on the desktop, the professionals in graphics-effects and computer animation - not necessarily real-time, but as quick as possible... The CUDA-using crew. The Tesla initative. This is an explosively-expanding and highly profitable business for nVidia - far more profitable per unit than any home desktop graphics application. An in-depth analysis by Anandtech of what the GT200 architecture brings to these markets over and above the current G8xx/G9xx architecture would be highly appreciated. I have a very strong suspicion that sales of the GT2xx series to the (ultra-rich) home user who has to have the latest and greatest graphics card is just another way of paying the development bills and not the true focus for this particular architecture or product line.

    nVidia is strongly rumored to be working on the true 2nd-gen Dx10.x product family, to be introduced early next year. Considering the size of the GTX280 silicon, I would expect them to transition the 65nm GTX280 GPU to either TSMC's 45nm or 55nm process before the end of 2008 to prove out the process with this size of device, then in 2009 introduce their true 2nd-gen GPU/GPGPU family on this latter process. A variant on the Intel "tic-toc" process strategy.
    Reply
  • strikeback03 - Tuesday, June 17, 2008 - link

    But look at the primary audience of this site. Whatever nvidia's intentions are for the GT280, I'm guessing more people here are interested in gaming than in subsidizing research. Reply
  • Wirmish - Tuesday, June 17, 2008 - link

    "...requiring fast number-cruching available on the desktop..."

    GTX 260 = 715 GFLOPS
    GTX 280 = 933 GFLOPS
    HD 4850 = 1000 GFLOPS
    HD 4870 = 1200 GFLOPS
    4870 X2 = 2400 GFLOPS

    Take a look here: http://tinyurl.com/5jwym5">http://tinyurl.com/5jwym5
    Reply

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