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How We Measure Noise

Tom's Hardware Graphics Charts: Performance In 2014
By

We measure each graphics card's noise levels with a calibrated high-quality studio microphone (supercardioid) 50 cm away from a position perpendicular to the middle of the board. This distance, as well as the strong cardioid microphone characteristic, represent a compromise between avoiding noise generated by the fan’s airflow and ambient noise that can never be completely eliminated. Our noise-dampening efforts certainly help minimize the latter, but they'll never be 100-percent successful. 

This year, we also had to decide (yet again) if we should use sone, dB, or dB(A) for our charts.

Decibel or Sone?

The definition of perceived loudness expressed in sone is based on sound pressure. One sone equals 40 phon, which in turn is defined as a pure 1 kHz tone at 40 decibel (dB). Sone scales with perceived loudness (that is, a sound pressure perceived to be twice as loud as 1 sone has 2 sone, and a sound pressure perceived to be half as loud as 1 sone has 0.5 sone). At first glance, this appears to be a logical, practical, and easy way to express noise level. Unfortunately, a closer look at how it works in practice reveals some irritating problems.

An increase in loudness by 10 phon from a starting point of 40 phon, totaling of 50 phon, results in a perceived doubling, which makes it 2 sone. However, the situation isn't straightforward under 40 phon. In that range, a reduction of less than 10 phon is enough to halve perceived loudness. And typically, the sound pressure produced by graphics cards at idle (along with quiet products under partial load) is almost exclusively below the 40 dB (40 phon, 1 sone) limit. So, recording an idle board's noise level in sone is difficult and potentially confusing. Overall, sone is better-suited to expressing higher sound levels.

Complex Noise Instead of Pure Tones

Another problem with sone is that it’s based on and scales with the perception of loudness of a pure 1 kHz tone. As we know, a graphics card's fan doesn't generate a pure tone at all. Rather, it produces complex noise covering a spectrum of frequencies.

The debate gets even more complicated when you try to compare noise from a centrifugal fan to that of an axial fan, and crazier still when you take different diameters and speeds into account. A sone value is strongly dependent on a graphics card cooling solution's specific sound profile, making the loudness rating it provides hard to interpret, even though that's theoretically the most exact way of expressing it.

The Human Ear

Coming back the other way, acoustic measurements use weighted sound pressure levels to reasonably model the human ear’s sound perception, simplifying our conundrum a bit. This is achieved through the use of filters, which are based on weighting curves defined in the DIN EN 61672-1/-2 norms. These filters are designed to provide a similar frequency response to that of the human ear for loudness measurements.

When you get right down to it, these are still only estimates. But, depending on the quality of your measurement device, they should be more representative for the range below 40 dB than sone values. Of course, providing dB(A) values only makes sense if the distance to the source of the sound is given as well (we make sure to do this).

With all of this considered, we'll keep using dB(A) for our noise measurements. Based on your feedback, though, I also want to give you the following table as a frame of reference. Hopefully dB(A) reference ranges with my own commentary adds meaning to the quantitative data that comes from our readings.

Audio Comparison Table
< 31 dB(A)
  • Very good cooling solutions at idle
  • Passively-cooled graphics cards
31 - 33.9 dB(A)
  • Mediocre cooling solutions at idle
  • Graphics cards with idle fan speed set too high (~40%)
  • Entry-level graphics cards with very good cooling solutions under full load
34 - 35.9 dB(A)
  • Entry-level graphics cards with average cooling solutions
  • Mid-level graphics cards with very good cooling solutions under full load
36 - 39.9 dB(A)
  • Mid-level graphics cards with good cooling solutions under full load
  • High-end graphics cards with very good cooling solutions
40 - 44.9 dB(A)
  • Mid-level graphics cards with below-par cooling solutions
  • High-end graphics cards with average cooling solutions
45 - 49.9 dB(A)
  • Generally loud graphics cards with below-par cooling solutions
> 50 dB(A)
  • Unbearably loud, usually graphics cards with reference coolers
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  • 0 Hide
    blackmagnum , May 11, 2014 11:29 PM
    Thank you Tom's team for updating the charts. You're my goto when I'm upgrading my rigs. I'll be waiting... Bring on yesterday's gems.
  • 0 Hide
    Pyree , May 12, 2014 12:50 AM
    Awesome!
  • 6 Hide
    outlw6669 , May 12, 2014 1:11 AM
    Nice writeup; I look forward to seeing the new charts!
  • 0 Hide
    tomfreak , May 12, 2014 1:11 AM
    First thing Tom need is to bench how PCIE 2.0 8x vs 16x perform on a modern top end GPU. Since 290X are passing the bandwidth from crossfire bridge to PCIE, may be is time to check them again? As I recall AMD do not recommend putting 290x XDMA crossfire on PCIE 2.0 8x. Please check this out
  • 1 Hide
    cypeq , May 12, 2014 1:42 AM
    First it's great to see new charts.
    I was never a fan of this style of benchmarking. It sure gives clean graph of gpu capabilities which we always needed. I would love to see new bottleneck analysis. Or at least parallel test done on midrange PC.

    Everyone should keep mind that these charts represent performance of <1% PC builds out there.

    Quote:
    First thing Tom need is to bench how PCIE 2.0 8x vs 16x perform on a modern top end GPU. Since 290X are passing the bandwidth from crossfire bridge to PCIE, may be is time to check them again? As I recall AMD do not recommend putting 290x XDMA crossfire on PCIE 2.0 8x. Please check this out


    If I recall correctly we are at this moment at the edge of PCI 2.0 x8 which = PCI 1.0 x16 . Next or following gen will finally outdate PCI 1.0 in single and PCI 2.0 in dual GPU configs as there will finally be noticeable bottle necks.
  • 0 Hide
    mitcoes16 , May 12, 2014 3:32 AM
    Any Steam OS or GNU/Linux benchmarks?
    It would be nice to add any opengl crossplattform game as any ioquake based one or something more modern and test it under MS WOS and under GNU / Linux

    Better if it is future Steam OS to let us know the performance at the same game under MS WOS and under GNU/Linux.

    Also it would be nice to test at MS WOS with and without antivirus, perhaps avast that is free or any other of your preference.

    Last but not least, in opengl or in directx there are version changes and being able to split cards generations by opengl / directx version support would help as a current price / performance index based in your sponsored links prices.
  • 0 Hide
    mitcoes16 , May 12, 2014 3:50 AM
    No 720p tests?
    720p ( 1280x720 píxels = 921.600 píxels) is half 1080p more or less
    1080p (1920×1080 píxels = 2.073.600 pixels)

    And when a game is very demanding or you prefer to play with better graphics playing at 720p is a great option

    Of course,latest best GPUs would be able to play at 4k and full graphics, but when we read the benchmarks we want to know also if our actual card CAN play at 720p (1k) or what the best ones can do at 1k to be able to compare

    Also even it is not a standard or accurate, for benchmarking purposes calling 720p (1k) 1080p (2k) and 2160p (4K) wouldbeeasier to understand in a fast sight than UHD FHD and HDR, that can be used too UHD (4k) FHD (2k) HDR (1k)
  • 0 Hide
    InvalidError , May 12, 2014 6:08 AM
    Quote:
    No 720p tests?

    720p does not stress most reasonably decent GPUs much and how many people would drop resolution to 720p these days with all the re-scaling artifacts that might add? In most cases, it would make more sense to stick with native resolution and tweak some of the more GPU/memory-intensive settings down a notch or two - at least I know I greatly prefer cleaner images over "details" that get blurred by the lower resolution and re-scaling that further distorts it.

    Considering how you can get 1080p displays for $100, I would call standardizing the GPU chart on 1080p fair enough: the people who can only afford a $100 display won't care much about enabling every bell and whistle and the people who want to max everything out likely won't be playing on $100 displays and $100 GPUs either.
  • 1 Hide
    2Be_or_Not2Be , May 12, 2014 7:06 AM
    I really like to see the charts on how much noise a video card's cooling fans make. That makes more of a difference to me as limiting something distracting that I hear every time I game versus getting a louder card with 10 fps more.

    I also like seeing how current cards stack up performance-wise to previous generations. That really helps when you're deciding whether to upgrade or not.
  • 1 Hide
    Ubrales , May 12, 2014 7:16 AM
    Thank you! Good reference article!
  • 0 Hide
    Zeh , May 12, 2014 7:46 AM
    WHAT?
    So you're not (directly) controlling the relative humidity of the air you're testing the GPUs in? You do know that it affects air's thermal capacity, huh?

    (I'm just joking, I'm glad you normalize temperature. Besides, by using an AC unit you're already putting a ceiling on RH%, thus controlling it Indirectly).
  • 0 Hide
    FormatC , May 12, 2014 8:41 AM
    @Zeh:
    The air-conditioner is only the last help. I'm living in Central Europe in the 1st floor of a a very old, historical building with very thick walls (up to 1 meter!). It is in the hottest summer impossible to reach more than 25 or 26°C inside (with closed doors and windows). This can be cooled down very fast and easy. Mostly I have to heat up my room :) 

    For the 720p lovers:
    I'll start after summer the entry-level charts with smaller cards and the same benchmarks - but lower resolution and settings for a better comparison. The difference between all cards is too large to put it into one database. This must fail. ;) 
  • 0 Hide
    voltagetoe , May 12, 2014 11:38 AM
    thanks for noise charting !
  • 0 Hide
    Tomtompiper , May 12, 2014 12:37 PM
    I know at this moment we only make up a few % of your target audience, but it is an increasing number, and a sea change is on the way. Could you please add just a few Linux benchmarks to allow us nerds to have an idea what the potential is for gaming on linux. I was lucky to be given an R9 290 (Gigabyte OC) for my latest build and I am more than pleased with the performance, however if I had to invest in a card with my own hard earned cash then a little information would be appreciated.

    However I appreciate the effort that has been put into trying to give some sort of comprehensive chart which can be of some use.
  • 0 Hide
    FormatC , May 12, 2014 2:01 PM
    Linux is a big problem because it extremely depends at the drivers. It is difficult to stay up2date with all this cards and I'm not able to re-bench all again and again due some funny driver changes over the year.

    I understand your interest but this is at the end a big time-problem. But it will be a good idea for a separate review with the most common cards. :) 
  • 0 Hide
    JackNaylorPE , May 12, 2014 4:59 PM
    1. Anything to address the new wrinkle of cards coming with two settings. I see the 290x for example with Quiet Mode and Uber mode but they both are going at the same 1000 speed ? If so what's the point of the having the option ? Would be nice to see just what the improvement speed wise is.

    AMD Radeon R9 290X Reference
    4GB Uber Mode / R9 290, 4GB GDDR5, 1000 MHz
    4GB Quiet Mode / R9 290, 4GB GDDR5, 1000 MHz

    2. Anything to address driver date ? ..... we all know that both teams make driver improvements but if a card is tested with version X.01 in May and then other cards are added in September, how do we compare the current performance of the May tested card w/ the current driver ZZ.01 and the September card with the current driver ? Will the tests be updated with driver revisions for apples and apples (current and current or release date and release date) comparisons ? Of course this is asking a lot but it would make the data more relevant.

    3. Any chance of getting a bar extension on those charts so that for example we can see just what a non reference card adds to the equation either outta the box or when OC'd "Bawlz to the Wall".

    4. Any chance of getting a specs chart for the "variations" as to what stock clocks are, base and boost, PCB, VRM phases, warranty, dimensions like the one here

    http://www.tomshardware.com/reviews/geforce-gtx-560-ti-roundup-asus-engtx560-graphics-card-overclocking,2858.html

    Yes, again asking a lot, but would make everything more relevant .... haven't installed a reference card in as far back as I can remember.
  • 0 Hide
    17seconds , May 12, 2014 7:39 PM
    So out of 8 gaming benchmarks, you're going to go ahead and have 7 of them come straight out of the AMD Gaming Evolved program? Several of these games are well-known to favor AMD cards disproportionately and feature AMD exclusive technology. At least one, Dirt 3, is played by no one, yet features a type of lighting that relies heavily on OpenCL to render, a well-known advantage for AMD cards. I'm not sure that's exactly defined as covering all the bases.
  • 0 Hide
    17seconds , May 12, 2014 8:27 PM
    I have always wondered why reviews don't list the ASIC quality score of the GPUs they are testing. Its so easy to get using GPU-Z and would help to create a nice database of ASIC scores that would allow us to draw conclusions about its significance.

    Do reviewers get cherry-picked golden sample GPUs for testing?
    Does company X bin their superclock/OC model chips higher?
    Does ASIC quality consistently mean better overclocking potential?
    Does ASIC quality have any significance at all in real world gaming?
    Etc.
  • 0 Hide
    FormatC , May 12, 2014 10:31 PM
    @17 seconds:
    - 90% of all cards are pure retail cards, no golden samples. All this was verified and proofed.
    - the Asic quality is more or less voodo. GPU-Z makes a lot of errors and it's not clear, which GPU-Z version gives you which result.
    - I've tested a handfull of 290X f.e. and the bechmark results were mostly similar. But the power consumption not (up to 5% difference)

    As I we wrote in the article - the selection of benchmarks is the result of a long selection process and if you take a look at the normalized results (index) you can see, that this results are very close to the average of other sites. For all this benchmarks the driver war is more or less over, so we get stable results over a longer time. All exclusive things were not used as StressFX or PhysX, some anti-alisasing options or lights/shadows.

    If I see from company A or N some significant driver improvements, I'm able now to re-bench all the stuff partially. This was done one time with the latest Wonder-driver from Nvidia a few weeks ago. And Dirt3? OpenCL is public, not AMD-exclusive. It is Nvidias part to improve finally the OpenCL performance, because it is 100% a driver issue. :) 

    The difference between quiet and uber mode is with full heated cards (and normalized over all benches) below 2%. You can hold in therory the clock rates a little bit longer but after heating and reaching the target temperature above 90°C all this reference cards increases the clock speed to hold it. This "uber mode" is only used to disguise the weakness of this really horrible cooling solution for a few minutes longer.

    And finally:
    I will bench all reference cards first to make an overview, but I'll also add the results of custom cards later - periodically, each month. I'm not able to write reviews and bechmark more than 20 cards per month at the same time. The current charts content was produced within 2 months and I'm sure that this is a good base to extend it step by step.
  • 0 Hide
    walshlg , May 13, 2014 6:46 AM
    How about a better test of graphics card performance: 3D. Sure not much 3D these days due to outrageous monitor pricing but next year with the Occulus and Sony 3d Headmount displays we will need something to compare cards with.

    In addition, most games don't really stress out a good card. Try 3D on a 4k monitor on 3D and then we can really talk about a stress test and performance gains that make a difference in gameplay.
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