Laptop Battery Life – 4K vs 1080P . We’re going to find out how much more battery power a 4K laptop screen drains compared to a 1080p screen. A 4K screen has 4 times more pixels than a 1080p screen, and the power for those extra pixels has to come from somewhere.
More graphics horsepower is obviously required to drive a larger number of pixels, but how much power does the display use, and does it make a practical difference to the overall battery life of your laptop? To test this I’ve got two laptops that are essentially identical in terms of hardware specs, with the only difference being that one has a 4K screen while the other has a 1080p screen.
Both laptops have an Intel 6700HQ CPU, Nvidia 970M graphics card, 16GB of DDR4 memory and an M.2 SSD. Both laptops have all Windows and Nvidia driver updates to date installed, and nothing else was running during testing. Although both laptops have the same size battery, are almost the same age and have had around the same usage, it’s possible that there may be small differences between the batteries, as use over time can degrade them.
I haven’t been able to accurately measure this, but wanted to point it out as it could be a contributing factor to consider. Despite this I think the two laptops are as close as can be and are ideal for this test. I performed testing using the Heaven benchmark. I mostly picked this because it runs on an indefinite loop and I could just leave it running until the batteries ran out.
Both laptops are capped at running the benchmark at 30 FPS from Nvidia’s battery boost feature, I could have turned this off, but I was concerned that by allowing the graphics cards to max out the battery would drain faster, making it more difficult to see what we care about, a difference in screen on time, if any. Also by capping the framerate to a solid 30 on both laptops I think we have more of a guarantee that they’re doing the same amount of work.
In the first test, the 4K laptop also ran the benchmark with a 1080p resolution, that way I could be sure that the graphics card was really doing the same work as the 1080p laptop, so basically the tests should be as close as possible allowing us to try and determine if there is any difference based purely on the pixels being powered in the display. In this test the 1080p laptop lasted for just over 7 minutes more than the 4K one, so there’s a little difference there which seems to indicate that the 4K display is reducing battery life due to the extra pixels.
Next I’ve run the same test again, except this time the 4K display is running at a 4K resolution, and again I’ve left it capped at 30 FPS so that we get the same experience as the 1080p in terms of FPS. This test should show a larger difference in battery life as we’re now accounting for the extra work the graphics card needs to do to actually render at 4K, whereas before it was just upscaling from 1080p to make use of all available pixels.
The results clearly show that the laptop with the 4K display is running out of battery much faster now, owing to the fact that the screen is powering 4 times more pixels. The battery life is only just over half as good when compared to the 1080p laptop. Although this test is very a small sample size, I think it goes to show that there is some justification to 4K displays using more battery power, and is therefore worth considering when buying a 4K laptop.
Just powering the extra pixels uses a little more battery, while the extra stress on the graphics card at 4K almost halved the battery life. I’m not a fan of having a 4K screen in a laptop, mostly because of how bad so many apps scale, it’s just a poor experience, and now that I’ve confirmed how much more battery is required to drive the display I’m kind of glad that I still run with 1080p on all my laptops.
Of course this is a personal choice, if you’re after a 4K laptop just keep in mind that it will use up your precious battery life faster when compared with a 1080p panel. So what did you guys think about the power difference between 4K and 1080p displays? Will it affect your choice when buying a new laptop? Personally I wouldn’t get a 4K display on a laptop for many reasons, but this is another reason for me to stay away from 4K for now.
Let me know your thoughts down in the comments, and leave a share on the post if you found the information useful. Thanks for reading, and don’t forget to subscribe for future tech posts like this one.