How Bright Do You Keep Your Notebook Screen?

By  |  Friday, June 12, 2009 at 12:38 pm

(Here’s another guest post by Pat Moorhead, Vice President of Advanced Marketing at AMD. Pat’s postings are his own opinions and may not represent AMD’s positions, strategies, or opinions. You can find Pat at Twitter as @PatrickMoorhead.)

The current defacto standard used by PC makers to measure notebook battery life is MobileMark 2007 (MMO7). This piece takes a look at the basic facts behind the notebook brightness settings recommended by MM07, comparing that to some typical home electronics devices and the average settings some consumers are using for their notebook displays.

The facts about MM07 and notebook display brightness

MM07 requires the following: “The display brightness should be measured for a white screen while on battery and be set at the lowest possible setting, no lower than 60 nits.”

So what is a nit?  Wikipedia defines a nit as a “candela per square meter.” Think of a “nit” as a unit of measure of brightness.

How does 60 nits compare to brightness of other home electronics?

To see what 60 nits relates to in real-world usage, we tested some typical home electronics devices  without changing any settings, other than shutting off “auto adjustment” on the phones.

Here are the test results:

Device

White Screen

Nits (cd/m2)

MM07

“X” MM07

BlackBerry Bold

Memopad

338

60

5.63

BlackBerry Storm

Memopad

326

60

5.43

iPod 80GB

Menu

311

60

5.18

Archos 7

Background

260

60

4.33

Optiquest Q9

Notepad

235

60

3.92

iPod Touch 32GB

Flashlight

225

60

3.75

Viewsonic VA912b

Notepad

188

60

3.13

T-Mobile G1

Flashlight

181

60

3.02

NEC Multisync 1700V

Notepad

173

60

2.88

Dell XPSOne

Notepad

155

60

2.58

The lowest nit measurement observed was at least two and a half times brighter than the MM07 brightness level of 60 nits on which notebook battery life is measured.

To see how nits relate to notebook screen brightness, we tested a few notebook PCs to see what the “max nits” measured when the screen was set to the highest setting.

As you can see from the figures below, the MM07 requirement was between 20-30 percent of the sample notebooks’ maximum screen brightness.

Max Nits

MM07

MM07 %

“X” MM07

Mac Air Gen 1

310

60

19.4%

5.17

MSI X340

214

60

28.0%

3.57

HP dv2

195

60

30.8%

3.25

What notebook display brightness setting do consumers use?

These results were interesting enough to prompt an informal poll of Twitter and Facebook users asking about the display brightness setting on which they place their notebooks. The responses are both qualitative and quantitative,.

Quantitative: Neowin actually placed a poll on their community website asking the question, “What brightness level do you run your notebook?”  More than 1,100 community members voted in a few days, and according to Shane Pitman, Editor-in-Chief, “Polls require a member account, and to be logged in to said account. Provides accountability, keeps people from voting multiple times.”

The results were overwhelming in that 75 percent of the Neowin community member respondents kept their notebook display brightness between 61 and 100 percent.

Qualitative: These responses were as valuable as the quantitative as they gave insight into why they did this.  Some comments gave insight into the folks who use their notebooks at very low display settings.

The following question was posed on Twitter  Research question: what display brightness do you run your notebook at? (Please RT)”.  Here is just a sampling of public tweet responses.

  • “On the machines I see, normally I prefer to have them fully backlit with the slider up to around 75% or so.”
  • “I run my laptop at maximum brightness unless the battery is really low, or I have an external screen. “
  • “Now running MBP 15.4″ 3.1 at 75% brightness with auto adjust turned ; but was at 100% without auto adjust til you asked! “
  • “90 – 100% brightness, 90% of the time. “
  • “depends entirely on my battery level and surroundings. “
  • “Research question: what display brightness do you run your notebook at? (Please RT). I run full bright 95+% of the time. “
  • “oh sorry :), 100% unless I’m running low on battery, where I bring it down to a minimum, I’m guessing 50%, but thats rare“
  • “usually around 60-70%“
  • “i don’t use them much, mainly desktop, but i either have brightness at full or minimum: latter at night and if battery low“
  • “When running laptop on battery, i set brightness to 25-40%, when plugged in -100%.“
  • “100% brightness. Left default setting (and I appreciate it that way… old eyes). “
  • “slammed up to full when possible, monitor screens vary though“
  • “mine is usually as bright as I can make it. I hate dim screens. “
  • “max brightness notwithstanding battery impact. “
  • “I lower my screen brightness to the lowest, usable level that’s comfortable. It’s all about the battery life. ;)
  • “Agreed…I think mine is usually around 30% or so. “
  • “it varies by location due to lighting levels. Usually around 30% or 40%. Never > 50% when on battery. “
  • “ME: 90 to 100% on AC, about 50 % on battery when I’m watching movies and about 20 to work. “

We also received some really interesting responses related to interpretation, explanations, tools and resources on brightness after asking about “60 nits”.

  • “not all that hard. Need 800+ nits to read screens in direct sun, 30-150 for night highway signs: http://bit.ly/cjxJB
  • “60 nits = table in an office with 300 lux illumination: http://bit.ly/FvoKe BTW sRGB calibration target = 80 nits. “
  • “oh and here’s a Kodak guide on how to use a digital camera and gray card as an ad-hoc nit estimator: http://bit.ly/1IMLK3

The Bottom Line:

  • The MM07 test requires a 60 nit or higher display brightness. To maximize battery life benchmarks, systems are set at the minimum allowable 60 nit level. This setting is thereby integrated into this battery life benchmark that is then used in notebook PC advertising to consumers.
  • Worst case, the display brightness of many home electronics is 2.58 times more than the MM07 nit setting requirement.  Based on the small set of notebooks tested, MM07’s 60 nits equated to around 20-30 percent of the maximum notebook brightness.
  • Unscientific querying on Twitter and Facebook says many classes of users crank their screen beyond 61 percent, and many at maximum brightness.  Some self-selected a lower brightness setting to conserve battery life.

Does MM07 use realistic notebook brightness setting in its battery life tests that consumers make buying decisions from?  You be the judge.   Whether you agree or disagree, what are your thoughts? And here’s a quick poll:

 
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6 Comments For This Post

  1. John McElhenney Says:

    A nice post Patrick. I could care less about a NIT = what.

    What the MM07 requires the following: “The display brightness should be measured for a white screen while on battery and be set at the lowest possible setting, no lower than 60 nits.”

    [Aside: Whatever a NIT is, and you do a fine job giving me references to understand it for myself. Could we go back to Candlepower? That at least had a frame of reference. Anyway...]

    So what the MM07 measurement is, if your quote above is accurate, is this: Take your laptop and turn the backlighting down until the screen goes black. Click back up ONCE so that you have your back lighting turned on, at the minimum.

    Now, would ANYONE CHOOSE TO USE THIS LIGHTING LEVEL if it weren’t for sucky battery life? Seriously?

    So as you have said before, Patrick, LET’S GET REAL WITH BATTERY LIFE STATS and MEASUREMENTS.

    So what is the OTHER measurement standard you are recommending? And what makes it a better case for our evaluation? And might AMD come out more favorably in that test, or are you merely pointing out a flaw in the current measurements.

    Frankly, I am not that concerned with battery life. If I can make it through a couple meetings untethered and plug in again when I get back to my desk, I’m golden. For those real Digital Nomads, hitting the airport circuit on a daily basis, I assume the issue is much more critical.

    And if I had to keep my screen on MIN Brightness all day, just to survive, well, I’d be pissed and looking for a different laptop/processor/battery.

    Thanks for you honest dialogue Patrick. And Happy Friday!

    @jmacofearth

  2. Marc Says:

    I always have it at 100% when plugged in, or at 60% if on battery but near a power point. If I’m away from a power point, then I’ll knock it down to 25% (this is a 17 inch HP beast, I get 2 hours max)

  3. Patrick Moorhead Says:

    @jmacofearth We are suggesting a min-max approach like cell phones (standy/talk) and auto mileage (city/highway). One measurement is simply not enough.

    Specifically, we are suggesting “Active hours/Resting hours” that communicate the notebook’s “resting time” (hours) and “active time” (hours) to provide a better indication of what the user will get.

    Here is what it could look like as a logo: http://blogs.amd.com/nigeldessau/wp-content/uploads/2009/04/batlife-metric1.jpg

  4. Dave Barnes Says:

    Bright enough that I always wear sunglasses when coding.

    Bright enough that my body manufactures all the vitamin D that I need. No reason to ever leave my basement.

    Bright enough to take full advantage of the plutonium-powered electrical generator that I have installed underneath my back yard.

  5. Marc Says:

    What about CPUs? I scale mine down to 50% when on battery. I wonder what the optimal is?

  6. John McElhenney Says:

    Here’s an update about Apple’s new MacBooks with non-removable batteries. What is great is the REAL WORLD test they put the MacBook Pro through:

    Over at AnandTech, the new 15″ MacBook Pro was pitted head-to-head against a recent vintage of the previous model. Anand Lal Shimpi says the fixed, flat-pack battery gives the new MacBook Pros “the best battery life I’ve ever seen.” When running on the integrated GPU in the NVIDIA GeForce 9400M, playing iTunes steadily in the background, and loading a series of 20 webpages every 20 seconds, the MacBook Pro ran for a few minutes over eight hours. That bests the previous unibody MacBook Pro by three hours.

    Several different tests gave battery life results anywhere from a 50 to 100 percent improvement over the “old and busted” previous gen. Since the new non-swappable battery only has 46 percent more capacity, Shimpi believes Apple has done a lot of optimizations across all the hardware to eke out every last bit of power savings.

    “There’s no other way to say this,” wrote Shimpi. “If you care about battery life and portability at all, buy the new MacBook Pro. Go to the Apple store and buy one.”

    ARSTechica article: http://bit.ly/macbattery

    @jmacofearth

3 Trackbacks For This Post

  1. When are Laptop Battery Specs Going to Get Real? | uber.la Says:

    [...] Additional Links: Technologizer: How Bright Do You Keep Your Notebook Screen? By Patrick Moorhead, June 12, 2009 [...]

  2. Resolved: We Need More Realistic Notebook Battery-Life Claims Says:

    [...] they feel high in many cases. Last year, AMD’s Pat Moorhead guestblogged here and noted that PC manufacturers’ battery tests tend to involving cranking screen brightness way, way down. But I do that myself–and turn off features like Bluetooth, and opt for “power [...]

  3. Resolved: We Need More Realistic Notebook Battery-Life Claims | Ranceo Says:

    [...] they feel high in many cases. Last year, AMD’s Pat Moorhead guestblogged here and noted that PC manufacturers’ battery tests tend to involving cranking screen brightness way, way down. But I do that myself–and turn off features like Bluetooth, and opt for “power saver” [...]

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