PWM Ranking - Notebooks, Smartphones, and Tablets with PWM

[Redaktion]

We use our PWM ranking to show you all notebooks, smartphones, and tablets we checked for PWM flickering of the display, which can be a problem for the eye.

http://www.notebookcheck.net/PWM-Ranking-Notebooks-Smartphones-and-Tablets-with-PWM.163979.0.html

[Matteo Barazzutti]

Hi,
And congratulations for the Great article! Im currently looking for a 13 inch laptop possibly pwm free. Ive got a 1000 € budget. I was wondering if the xps 15 with the i5 does use pwm in all its versions or rather this problem has been fixed with the 2016 refresh. Which alternatives can i get with that money?

[Matteo Barazzutti]

Sorry i meant xps 13

[RJ808]

I have the same question.  I saw one report that the Dell XPS 13 did use PWM, but this had PWM listed at 0.  Anyone know for sure? Thanks!

[Nikita]

A bit of warning, same laptop/smartphone models might be using various panels, some might be flickering and some not. I am very sensitive to it and I was looking specifically for a flicker-free screen and purchased Dell E5570 which was reported by multiple sources to have a flicker-free Samsung panel and by some sources to have an AUO panel (many AUOs are flickering and literally caused me a lot of headache). One I received had a BAE panel. Fortunately, flicker-free. Be careful.

[Sven Nikolajsen]

Hi, unfortunately I am one of those people who can not endure PWM Backlight controls. My questions are
1: Why not measure from 1 Hz on?
2. When you make does measurements is it from 100% light on or 50% - I would be a lot more interesting from 50% on so people do not have to worry about that. Alternative you could measure both.
I know some Eizo monitors they change to pwm when you lower the light to a certain procent - I have one of them.
I am thinking about buying the Iphone 7 plus - In your else excellent review of the phone you write it is PWM free - Do you have it measured in different light levels? If so I would really like to see them.

Yours sincerely
Sven Nikolajsen (Denmark)

[Klaus Hinum]

We measure all the frequencies our testing equipment is able to report. That should be from 1Hz (altough that would be way too slow, everyone would notice the flickering) up to the kHz range.
We look at what ranges the flickering happend and note it in the review, e.g. if it only happened from 20% to 80% brightness, that should be noted.
Regarding the iPhone 7, yes we measured it with different brightness levels, but usually we only add one screenshot.

[Jaimi]

The Graphics Cards are all listed as the same model for some reason.  Was there a glitch or mistake made?  Not sure when this happened, but it wasn't like this last I checked a few months ago

[Klaus Hinum]

Thanks, mistake - fixed
GPU Models should be now visible and linked to the gpu page.

[Tomas]

Ich muss sagen, dass dieser Ranking auf noteboockchek.com ist ein totaler Witz ist. Ich bin sehr sensible auf PWM und kann sagen, dass einige Laptops und Smartphones die in der Liste las PWM frei angeführt sind, benutzen PWM. Laptopmedia Seite hat eine ähnliche Liste, mit viel weniger Laptops drin - ca. 10 -15 pro Hersteller über 3-4 Jahre - und die machen auch eine Messung unter Lab-Bedingungen. Hier bei Noteboocheck.com wird angegeben, dass sie bei über 50 % der Laptops kein PWM feststellen konnten. Woher also diese krasse Diskrepanz bei den Messungen? Da die meisten Menschen auf PWM nicht mit solchen Kopfschmerzen wie ich reagieren, kommen die Autoren von Netoboockcheck mit dieser Lüge offensichtlich durch ... Ich will nicht mutmaßen, warum die Leser hinters Licht geführt werden ...

[Tomas]

I have to say that this ranking is a joke. I have already ordered couple of smartphones and laptops that are here as PWM free and they were all using PWM - and yes I checked the dispaly used in the laptops. I mean notebookcheck attest over 50 % of all laptops to be PWM free. There are other sincere Websites like Laptopmedia which has a PWM ranking featuring 10-15 Laptops per Manufacturer as PWM free over a period of 3-4 years, so one might ask where does the discrepancy come from. Many readers are not so sensitive to PWM as I am, so the Authors come with such blatant lies through. And manufacturers know that even readers that do not get instant headaches from PWM do not like the idea of LED light constantly flashing infront of their eyes...
If only all PWM sensitive people would voice their concern over this BS ranking ... I think such dishonest rankings are actually much worse than no rankings at all, becasue without trasnparency no change in the production will come.

[Benjamin Herzig]

The problem is that its a standard industry practice to use displays sourced from multiple manufacturers for the same laptop. So while the unit we test might be PWM free, the next one under the same model name might have PWM - while they should be identical on the specsheet, in reality, they are not.

This is a problem impossible to solve for us. We at Notebookcheck can not test every single Notebook on earth and its almost always impossible to tell how many different display.panel variations there are for a product, because the manufacturers are mostly intransparent about this stuff.

In the end, its the manufacturers who are not transparent about their products. Its their task to make more honest spec-sheets and inform people about their products.

[Franck]

Thank you so much for this fantastic article!!!

[AG]

 Hi,

very helpful article, thank you!
I am trying to figure out the origin of my terrible eyestrain and almost instantaneous cervical pain upon using certain devices, pc monitors, laptops and now, unfortunately, phones.
I have had a Samsung Galaxy On5 smartphone for nearly 2 years. I have never suffered of any condition. I can use the phone to read e-books for hours. Very recently I bought a Freetel Kiwami 2 which mounts a 5.7" OLED display and immediately developed severe symptoms. Besides the feeling of eyes filled with sand, the soreness and the difficulties associated with focusing on different objects close to and far from the device, my visual discomfort would quite immediately turn into cervical pain, which I find puzzling because I clearly do not assume a different posture to when looking at my Samsung Galaxy On5.

I now wonder whether the reason for my disturbs is PWM. However, I see none of these phones has been reviewed. Is that correct?

I have a couple of other questions/comments. I am sorry if I incorporate a lot of topics but I am quite desperate and I really want to dig out some helpful information from experts in the field and people suffering of the same problems. Indeed I have not found any competence nor interest at medical / optometrist level. I start with my queries...

I see that the top ranked phone as to Response Times PWM Frequency is the Nomu M6 and at the bottom of the standings there are devices with zero frequency. Assuming I suffer of PWM-induced symptoms, shall I opt for a smartphone with the highest PWM frequency or with zero frequency? If I understand correctly, zero frequency means that PWM is not employed so brightness dimming is attained without turning the backlights on and off. Could you please clarify?

On a different note, I do not see the MacBook Air (13-inch, Early 2014) in the list, probably it is a bit old. Can anyone comment on PWM with regard to this laptop? Is it very different to the 2017 MacBook Air present in the rankings, scoring a PWM frequency of 58K Hz?

Furthermore, I would like to ask if the display resolution can affect the PWM frequency. I would think it is two separate things. However, historically I noticed that my disturbs would disappear by changing the display from native to a lower resolution. As an example, in 2006 I bought a Lenovo ThinkPad T60 and I could not handle the display from the eyestrain. Then I lowered the display resolution to 1024 x 768, and I could comfortably use the laptop, staring at the display for 15 hours a day without any collateral effect. Someone could argue feature miniaturization under native resolution could be the reason of my eyestrain. However, I would develop symptoms even if I did not read, just by staring at the display. If at the highest resolution of my laptop I increased the zoom considerably to make the features of the same size as with the 1024 x 768 resolution, I would still have issues.
At lower resolution my eyes do not seem to detect all those pixels flashing in the background. Does it make any sense?
I used the same "trick" with a Dell Latitude more recently, I forgot the model, and with some monitors.

Another point I would like to ask about is the impact of the graphics card on the display and on eyestrain. I read some posts about some graphics cards, specifically from one manufacturer, generating eyestrain in a minority of people. I am sorry I am not allowed to post links as a new user...
I found myself quite in good agreement after checking which computers were tougher on my eyes. They all had an Intel card, but I am very cautious with this. Could it just be a coincidence?
What leaves the doubt is that in a couple of occasions I had to use two different pcs in the same laboratory connected to the same model of monitor. One would give me absolutely no problems, the other monitor would drive me crazy. Graphics card was the only difference I could tell between the two setups.
Another potential evidence. I talked about my Lenovo Thinkpad T60 and how I worked around my eyestrain by lowering the resolution to 1024 x 768. The laptop mounts an Nvidia card. Well, a few months ago I had the bad idea of upgrading from Windows XP to Windows 10. I struggled finding online a driver for the graphic card. Is it correct that if the Invidia card does not get to work properly because of a lack of driver, there is a sort of basic card taking its place? I may be saying a stupid thing...In any case, I lowered the resolution of the display to 1024 x 768, and the eyestrain is very strong. It is the same laptop, and the same resolution!

Any thought?

Thanks so much for any comment, and sorry for the tons of questions! Hopefully it is not too difficult to get thru my post.

[Franck]

Awesome information, thank you so much!