The Lenovo ThinkPad W520 i7 Quad Core has seven hours of battery life? Really?

thinkpad w520 3When the rumors of the Intel “Sandy Bridge” chipsets started to surface, I was skeptical. It sounded too good to be true and frankly I started dismissing it as marketing.  The claims seemed outrageous.

Then I read one of the first reviews of a Sandy Bridge based machine, the Apple MacBook Pro, detailed by the highly respected AnandTech.  The MacBook Pros put in some rather respectable numbers for battery life.  I’m thinking, really?  A quad core with life beyond three hours?

Sure enough, the Lenovo ThinkPad W520 I am writing this on turned in 6.5 and 7 hours of battery life in my first two tests. I haven’t even turned on the “battery stretch” mode of Lenovo’s Power Manager program, nor have I turned off Aero Glass and all of the bells and whistles of Windows 7.  This is double, and in some cases, triple the battery life over the previous generation ThinkPad W510.

You might be thinking that the ThinkPad W520 clearly must be crippled and no longer deserving of the “workstation” designation.  Think again.  This baby is fast.  As you can see in the WEI result below, the W520 is knocking down a respectible WEI number.  As the moment I have the BIOS set in discrete GPU only mode.  Therefore the graphics number is for the NVIDIA Quadro 2000M side of the Optimus graphics chipset.


How did I conduct my battery tests?  Good question.  On both of the tests I wanted to simulate realistic activity I might be interested in on a long flight.  Usually when I am on an airplane I like to watch a movie or surf the web if there is WIFI available.  I fly a lot of American Airlines flights so I use GoGo Inflight Internet.  Both of the following tests were with Windows 7 Ultimate x64.

On the first test, I played some videos nonstop.  They were Windows Media Video (.WMV) files at various bit rates and screen sizes.  The video playback was either fullscreen or in a window.  Screen brightness was 11-13. WIFI was on and in use the entire time.  I had Tweetdeck running fullscreen during the entire time.  Tweetdeck is a really chatty program and I like to use it for this type of test because there’s no way the WIFI device is going to get powered off due to inactivity. This test lasted 6.5 hours.  I couldn’t believe it.

For the second test, I recharged the battery overnight.  I disabled the WIFI device (Intel 6300) and didn’t use any other programs. Screen brightness was 11-13.  Most of the time it was set at 12 or 13.  I fired up a movie and let the test run.  It lasted 7 hours this time.  Obviously this wasn’t a fluke.  I’m impressed.  Most of the W510 owners I know get 2-3 hours of battery life so 6.5-7 is clearly miraculous.  I haven’t even tried the really harsh “battery stretch” modes of the ThinkPad Power Manager.

I will write more detail later on this machine, impressions, and results but I thought you would be interested in the battery life which still has me floored.  I would certainly like to see that kind of battery life in my ThinkPad W510. 

One other thing.  The picture of the ThinkPad W520 at top right in this article was doctored by me.  I took the stock W520 image then added a screen shot of my Windows Server 2008 R2 SP1 desktop.  In the screenshot I have Hyper-V running, the Hyper-V management console, and a R2 SP1 virtual machine running.  Windows Server R2 SP1 installed very cleanly on the ThinkPad W520.  I also have themes and Aero enabled (just for grins). I’ll provide some notes on R2 installations later.

Looks like another killer offering from the folks at Lenovo.  More details coming later. Enjoy.

[UPDATE for 3/25] Someone asked about the power brick.  Here’s a comparison of the 90W, 135W and the 170W.  Keep in mind the 170W weighs less than the 135W.

[UPDATE for 3/29] Both machines were using Intel 160GB Gen 2 SSD drives in the test runs above. The W520 was in Optimus graphics mode. I am running a test right now where the W520 is using the 500GB Seagate hard drive, and it’s set to discrete only video. After I run this a couple times, I’ll report back. My guess is that it will have a significant impact.  More later.

[Update for 3/30]  My ThinkPad W520 is getting four hours of battery life when the BIOS is set to use only the NVIDIA 2000M discrete GPU.  For these tests I was also using the 500GB 7200rpm Seagate laptop drive to serve up the video.  The movie ran continuously during this time.  I also had the Intel 6300 WIFI adaptor enabled and Tweetdeck was covering about 66% of the screen.  The screen brightness was sitting at 11 during the entire time.  This is still pretty darn good considering. Moral of the story: use Optimus when you need to stretch your battery life.

Also, I noticed in the forums people are curious about the use of the 90W adaptor so I ran more tests with it.  If the ThinkPad W520 is turned off, the 90W will charge the battery back up.  Therefore, you could re-charge the battery at night while you sleep.  However, the 90W will not maintain that charge when the machine is powered on an in use so I don’t think it’s a good travel strategy.  I don’t have a 65W charger.  I used to, but I think it went out the door with one of the children and never came back.  As usual.

[UPDATE for 4/11/11] The previous tests were based on the Lenovo factory image.  Not long ago I flattened the machine and rebuilt it from scratch using the drivers on  I also decided to see what battery life was like with “Keith’s Max Power Savings”.  That’s a custom power plan and profile I created using Lenovo Power Manager and the Power Options Control panel applet. It’s basically my version of a power source optimized environment.  Very stingy on battery.  Very powerful but not maxed out when plugged in.

The results were better but not earth shattering better. I did two tests that were similar to my previous test.  In the first test, the WIFI adaptor is enabled, Tweetdeck is running and updating the entire time, and a video is playing.  I noticed in my settings review that the WIFI adaptor wasn’t in the most miserly setting (see below). At the lower setting it might have added 15 minutes of life.

For the video I used an HD 720p sized video with a 3.5MB data rate in .MP4 format.  The movie is 2:30 in length and I set it to loop continuously. The machine died on the vine at 6 hours 25 minutes.  I have the power plan set so that the critical percentage is 0 and to take no action.  It literally runs until it dies.

For the second test, I disabled the WIFI adaptor and didn’t run any apps other than the video.  Both tests had the screen brightness set at 10.  This test managed to squeak out more time as expected and it died at 7 hours 23 minutes.  Both of these tests were using Intel SSD drives as the source for the video file.

Here are some key notes on the settings I am using to achieve these longevity scores.

BIOS - Graphics Device=Optimus, OS detect for NVIDIA Optimus=enabled, Intel SpeedStep mode for Batt=Battery Optimized, Thermal mgmt scheme for batt=Balanced, Optical drive speed=norm, CPU power mgmt=enabled, PCIE power mgmt=enabled,

DC Power Plan Settings - system perf=low, cpu deeper sleep=enabled, fan=balanced, display brightness=10, optical drive power off=enabled, dim display=never, lower display refresh rate=15 minutes, lower to=50Hz, turn off display=never, stop hard disk=30 secs (but irrelevant), standby=never, hibernate=never, pcie link state power mgmt=max power savings, multimedia playing video=optimize power savings, USB selective suspend=enabled, slide show=paused, sys cooling pol=passive, low batt alarm at=0%, notification=none, action=nothing, reserve batt=0%, crit batt alarm=0%, action=nothing.

DC Control Panel Power Settings - there is a lot of overlap between the two plans and they each don’t have all of the other’s settings so you need to watch carefully which plan clobbers the other.  Here are the unique settings only in the control panel applet. WIFI adaptor power saving mode on battery=medium (an error on my part), Intel Graphics Power Plan=max batt life, min processor state=5% (default), max processor state=5% (default), IE9 JavaScript Timer Frequency=max power savings.

I have never messed with the minimum and maximum processor state percentages but I might do that on a future run to see if it has an effect.  I have not tested “battery stretch” mode either. I’m pretty much done testing battery life.  Seems pretty good for a quad core notebook to me.  Certainly good enough for my needs.

IMG_1163IMG_1164 Click the image for a larger view.

Comments (25)

  1. Peter Kellner says:

    Hey! how did you get one?   I thought they don't come out until next week sometime.  BTW, how big is the power supply? will I need another backpack to carry that around in?  Which model are you using?  I order the 2820 because the difference to the 2920 was $1000 (and included the faster graphics and some more memory, but didn't seem worth $100).…/always-wanting-the-latest-fastest-lenovo-thinkpad-info-on-w520-follows

  2. tom says:

    how do you already have a w520…i thought they were released next week?

    thanks for the great post…can't wait to hear more!

  3. Keith Combs says:

    The power supply is rather large.  It's really the size of a standard brick. The 170W brick actually weighs less than the 135W brick that comes with the W510.  The 170W is 770 grams and the 135W is 830 grams.

    Regarding the backpack, it fits nicely in my Wenger Synergy which is a standard size pack available nearly everywhere.  It's one of the best backpacks on the market as far as I'm concerned.

  4. Keith Combs says:

    Tom, mine shipped last Saturday from China and I received it Monday.

  5. tom says:

    great blog.  but how did you even order it?  just curious.  

    i'm probably gonna be purchasing one next week after they are released and would love too hear your initial impressions of the next couple of days

  6. Keith Combs says:


    Thanks for the blog compliment. As you might imagine, we get to test a lot of machines long before they are known publicly. I rarely get to talk about them until right before their public release.

    I usually get early looks at some of the machines that are likely to become internal standards for our Consultants, Technology Specialists, and other technical personnel. It's one of the reasons I typically install Windows Server and the virtualization products right away.  If there's a fatal flaw, I usually find it.

    The W520 is looking really good so far.  I will write a detailed review before long.  Take a loog at some of my ThinkPad W510 posts to get and idea of my style.


  7. carl l. says:


    The power supply is ridiculous big, something from the 80's,.. is it really not possible to design a smaller unit in 2011?

  8. Keith Combs says:

    Yea, well, at least it doesn't use a 230W power supply like the HP. Gotta look at the bright side. 🙂

  9. Peter says:

    Hi Keith, I am thinking of picking up one of these babies soon. Can you tell me if the DC connector on the 170W power supply is the regular 20V connector on both the 135W and the 90W supplies, or did lenovo change it?

    I already have a dock that I use for my T410s and would love to use the same dock (with the 170W power supply) with the W520 when it arrives.


  10. Keith Combs says:


    The connector did change. You cannot use the 170W power supply on the T410s. However, the W520 does seem to work fine with the 135W power supply and dock.  I have one for my W510 and T410s. I will be writing a detailed review over the next couple of days but I want to test driving multiple monitors from my dock (at least three) first.

    Therefore, hold additonal question not related to power and battery life for that article.



  11. DavidReller says:

    Does your model have a 6-cell or 9-cell battery?  When your full review comes out, I'll need something to collect the drool… 🙂

  12. Peter Kellner (aka: someone) says:

    I know you said "hold off the question", but I just can't seem to stop myself.

    Do you know if the you can use the 90W Powersupply to either charge while off, or run without charging?  Also, you mention that it is smaller than the W510 charger (which is heavier than my wife's computer).  How big is the w510 compared to the w520's?  Is it pictured above?

  13. Dennis Jensen says:

    There seems to be quite a bit of sites where it states that the W520 supports up to 32Gb of RAM. However on all official Lenovo papers and specs that I can source, the maximum RAM limit is 16Gb. Does anyone know if it is indeed 32Gb or 16Gb?


  14. Keith Combs says:

    Regarding the RAM, do you know how much 4x8GB DDR3 SoDIMMs cost?  If you did, you wouldn't ask the question.  They used to be $2000 USD EACH !!!  So to test the configuration you desire, we're talking about tossing 16GB and adding $6000-8000 dollars worth of memory.

    Needless to say, unless Samsung or Kingston decides to loan me some sticks, it isn't going to get tested anytime soon.  And if Samsung or Kingston is reading this, I'll be happy to test your goodies. 🙂

    I'm pretty confident the W520 and some of the other 4 SoDIMM slot notebooks on the market will go to 32GB, but will they go to 64?  Grin.

  15. Keith Combs says:

    I decided to open up comments on this article again now that I have the larger review completed and posted. Comment in either location. Cheers!

  16. Marcus Sweden says:


    I'm going to buy the W520 very soon, but I'm very curious about one issue that's really bugging me and that is the bad sound quality of my T410i and T510-series thinkpads. I have the X301 which just blows the other two away. I often work with Spotify and don't bother listening on headphones but on the T410i it is so bad I usually end up quitting Spotify all together. How is the sound on W520?

    Also, I didn't really understand if I can use my Dock Series 3 which I'm using to the T410i to the W520? Because if the power plug is different, it won't fit in the dock?

  17. Keith Combs says:

    Marcus, I have not tested any of my headsets or earbuds yet.

  18. tony says:

    Thank you for the thorough (mouth watering) review.

    Any idea would battery slice will give you? Double?

  19. Keith Combs says:

    Tony, I don't have a slice battery but I think I recall seeing some discussion about it in one of the forums.

    FYI, I am running some other battery life tests.  The original tests in this post were using the Lenovo factory installation. I am using a clean install with downloaded drivers for comparison.  I will update the blog post with details soon.

  20. Steve says:

    The W520 is being offered @ UNC as part of this years computing initiative( an all in one computer/service/sftware program). It's $500 more than the T420 and $700 less than the Macbook Pro 15 being offered. I want my kid to have something that will last 4 years of school, provide good value and quality.  I'd appreciate your thoughts on the choices. Thanks for the great blog!

  21. Zohaib says:

    Hi Keith, Just wanted to know if the 9-cell sticks out on W520s.

  22. terence says:

    Thanks for the info on the 90W power brick. I thought the 135W on my W510 was big enough already, don't think I will be able to lug the 170W one around.. Now I am thinking of upgrading to the W520, how is the performance on it if you just use the 135W brick?

  23. Keith Combs says:

    @Steve, sorry for the delayed reply. Of the three machines you mention, you really can't go wrong with either of them.  The T420 is the lightest of the three and when toting it in a backpack with books, it's probably the best choice.  All three of the machines you mention should survive college if they are well taken care of.  Not knowing the application mix makes it hard to really make a solid recommendation.

    @Zohaib, yes the 9 cell sticks out the back.

    @Terence, there is no performance loss on my W520.  The 170W charger is really for the extreme quad core top-of-the-line model with RAID and two hard drives.  

  24. Kathir says:

    Hi, How to change the automatic charging percentage in W520? I can't find it in Power Manager.

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