Curbing Your GPU's Power Use: Is It Worthwhile?

Conclusion: Doable, But No Walk In The Park

Pros and Cons

First things first: can you lower your GPU’s power consumption, particularly when you use it in games and applications? The answer is a resounding yes. You can pretty much use the same approach you’d employ if you were trying to cut the power consumption of your CPU. The difference is that graphics cards seem much more black-box in nature. Enthusiasts are less likely to tinker with them because granular settings are more difficult to access.

The methods range from very simple to not-so-easy, at least as they pertain to AMD’s graphics cards (an exploration of Nvidia’s solutions could be particularly interesting, given the company’s intention to protect its boards from overvolting with some sort of lock). The easiest strategy is running the card in UVD mode. You can use this trick on pretty much any Radeon card. And it’s great because those settings are already available by default.  That means your card continues to operate within its specifications.

However, if you want more significant savings, you’ll have to get your hands a bit dirty. As the results show, the biggest savings are enabled when you drop clock speed and voltage. In that case, your choices are limited to cards which have voltage adjustment features or selectable core voltages in the BIOS.

There is a matter of convenience. Although it is pretty easy to trigger UVD mode, doing so every time you want to play a game or run an application is not. Unfortunately, third-party apps don’t help much in this regard. For example, Asus’ SmartDoctor utility lacks an option to save profiles. Asus does offer another utility for tuning graphics cards called ITracker2, but it only works with the company’s Matrix- and ROG-series graphics cards.

There are other utilities like MSI’s Afterburner that can save clock and voltage presets, but its voltage adjustment only works with certain supported cards. If you have your heart set on trying this yourself, it would be wise to pick a card that provides everything you need. You need to check out graphics card reviews for detailed descriptions about bundled utilities.

Putting Things In Perspective

So, why would you do this? Saving power might be a great idea for the environmentally-inclined, but does it make sense financially? Particularly compared to simply buying a mainstream card right out of the gate, such as AMD’s Radeon HD 5770? We’re talking about 10% power consumption savings in desktop applications and between 15 to 25% in games, with about the same performance penalty (using default DXVA settings). With voltage adjustment, you could probably push that to around 30% (around 100 watts).

Just how big of a difference does 100 watts make, financially? Well, that’s about 0.1 kWh per hour, which is less than 1 cent per hour (depending on where you live and the rates your power company charge you). For most desktop users with a single PC, the savings are negligible at best.

What about other benefits, such as temperature and fan speed/noise? Here’s a look at both. We’ve taken the numbers from the Radeon HD 6970’s GPU-Z log running Medal of Honor.

Obviously lower clocks and voltages have other advantages, but mainstream cards also offer these same benefits. They also cost a lot less than high-end cards. So, what's the point then? One thing that most mainstream don’t have is performance. Mainstream cards may offer simplicity, lower power consumption, operating temperatures with less noise at a lower cost, but they don’t always have the performance. With a high-end card, you have more performance available when it's needed. From this experiment, we learned that they can be power savers, with a little bit of effort and luck.

The focus of this article was to find out if it's possible to have performance when you need it and power savings when you want with a high-end desktop graphics card. The answer is that yes, you can achieve both of those things, though swapping back and forth is hardly practical at this point in time. We have the hardware today, and that much is clear. Hopefully, we get more control from companies like AMD and the third-part software developers writing tools for its cards in the future.

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    Top Comments
  • hokkdawg
    Dude, I'm now feeling a sudden urge to watch The Matrix!
    21
  • Other Comments
  • hokkdawg
    Dude, I'm now feeling a sudden urge to watch The Matrix!
    21
  • Anonymous
    I think, considering those people using SLi and crossfire and higher end videocards, they don't really give a gat about how much elec. they are using. They can afford to buy two expensive PCBs, why would they care about extra 5~10 bucks per month? If poeple are focused on lower power consumption, they would go for lower performance components, arent they?
    8
  • anttonij
    I guess the most important point of this review is that you can lower the cards voltage while running at stock speed. For example I'm running my GTX 460 (stock 675/1800@1.012V) at 777/2070@0.975V or if I wanted to use the stock speeds, I could lower the voltage to 0.875V. I've also lowered the fan speeds to allow the card to run almost silently even at full load.
    1
  • Khimera2000
    @.@ there is no apple @.@

    This is neat though :) I wonder if this article might inspire someone to make an application. Come on open source dont fail me now >.
    0
  • Anonymous
    Could you do comparison of "the fastest VC" vs "entry level" and then show us how much money we might end up paying each month or day?
    -2
  • the_krasno
    Manufacturers should find a way to implement this automatically, imagine the possibilities!
    3
  • wrxchris
    @OvaCer

    I have 2 gfx cards pushing 3 displays, but I'm all for saving watts wherever I can. Our society has advanced to the point where sustainability is a very important buzzword that is widely ignored by mainstream media and many corporations, and this ignorance trickles down to the mainstream like Reaganomics. Minuscule reductions such as 30w savings across hundreds of thousands if not millions of users adds up to a significant reduction in carcinogenic emissions and saves valuable resources for future consumption.
    4
  • delinius
    Holy crap, I watched the Matrix again just before this topic was posted..
    1
  • neiroatopelcc
    So when playing video, you risk your amd card going into uvd mode? What models does that apply to?
    I want to know, cause for instance in a raid, I'd sometimes watch video content on another screen while waiting around for whatever there is to wait for. I already lose the crossfire performance because of window mode. I don't want to lose even more.

    Does my ancient 4870x2 support uvd?
    0
  • jestersage
    so... for the dual bios HD6900s, I can RBE one bios with my desired settings and just choose which bios to use before I power up my PC? hmmm... interesting.
    0
  • brendonmc
    Pretty pointless article which concludes the obvious.
    3
  • tommysch
    This is like trying to save gas with a Ferrari.
    3
  • feeddagoat
    tommyschThis is like trying to save gas with a Ferrari.


    With proper engine mapping, good throttle control, weight reduction from materials used, loosing carpets, spare tyre, radio etc. and the aerodynamic design of a Ferrari it isn't as stupid as you think.
    0
  • chesteracorgi
    Interesting. When I have time I will try lowering the voltage while maintaining the OC and see what happens.
    0
  • JackNaylorPE
    OvaCerI think, considering those people using SLi and crossfire and higher end videocards, they don't really give a gat about how much elec. they are using. They can afford to buy two expensive PCBs, why would they care about extra 5~10 bucks per month?


    At a full 8 hours per day, every day per month, you're talking $2.40 or basically the cost of one 12 oz. latte at Starbucks.
    3
  • Lrxst
    This should all happen automatically with a number of parameters set by the user, like motherboards. To me, fan noise is the biggest enemy, and a small power savings takes back seat. One of the downsides I see is if some manufacturers used a new power saving architecture as an means to take shortcuts in cooling their cards properly at full throttle.
    0
  • nukemaster
    I undervolt most of my cpus anyway
    0
  • RazberyBandit
    Here I thought that my two 4000-series systems (4850 and 4890), which do not reduce memory frequency in either 2D or UVD mode, were truly behind the times. It appears even 6000-series cards don't do it while in UVD mode. That alone is something which could be enabled by AMD and it's board partners on all new cards by default. But, seeing as the default memory speed provides the best benchmark numbers, that's likely the reason why it's not done.

    I typically use CCC's Overdrive to manually reduce memory speed while in 2D-mode, which works fine. Despite having been manually set, whenever it senses UVD playback (be it Flash, DivX, etc.) the memory frequency changes to it's default speed (1000MHz on the 4850, 975 on the 4890). Now I know why - once UVD mode is active, it's clocks reign supreme. It seems the only way to change that is to mod the BIOS.

    When it comes to general users, the end result of all this tweaking seems to unfortunately only save rather minuscule amounts of power.
    0
  • tommysch
    feeddagoatWith proper engine mapping, good throttle control, weight reduction from materials used, loosing carpets, spare tyre, radio etc. and the aerodynamic design of a Ferrari it isn't as stupid as you think.


    Those are performance modifications, less gas consumption might be a side effect but it is not the goal.

    The 599 is stupid, the 430 is godly.
    0
  • gm0n3y
    Or just save the hassle and buy a more efficient power supply. That has to be the easiest and best way to use less electricity.
    0