Dell M4800 - PWM (pulsed width modulation) free display options?

Dear Friends,

The Dell M4800 is a magnificent machine in terms of performance but I was very disappointed to see Dell has placed no attention to viewers eye comfort and the display that came with it (the HD LG Philips made display) seems to use pulsed width modulation (PWM) to dim the display. The display is too bright to use with the full backlight on (where there would be less or no PWM) but I do not understand why for the high end models DC method of backlight dimming and thus flicker free displays can not be used. Perhaps there is not enough requests or demands from users as this issue has not come into the limelight (excuse the pun) sufficiently.

My questions to those technically familiar with the innards of these systems and the Precision range are:

1.Is there any option to replace the display in the M4800 with one that does not use PWM. Does the Sharp manufactured QHD display also use PWM? Could one of the users having this display please run HWInfo and send the exact model of the QHD display in their M4800.

2.Are any of the Precision's PWM free (flicker free) ?

3.Whom to address at Dell about this issue going forward as the only solution now is to downgrade to the older models that used CCFL backlighting which are effectively flicker free.

For those new to this subject and how serious the impact is here are some threads:

http://www.eizo.com/library/basics/eyestrain/

This is in Russian but it reads fine when translated but shows you how you can measure PWM flicker yourself:

http://www.retropcmania.com/2013/03/analysis-of-lcd-pwm-with-oscilloscope.html

Kindest Wishes,

Leonard M

 

You'll be probably surprised by the amount (or rather the lack of it) of desktop displays that don't use PWM (very, very few), even EIZOs use PWM (not all of them). So, they are even less common in laptops. I'm not aware if any of the new models use PWM free back-light. The only (newish) laptop I know for certain that doesn't use PWM is 8740w, and that's for the nonDreamColor panels. The DreamColor is PWM, but I guess it's high-frequency, because it doesn't hurt my eyes while I'm using it at minimum brightness with occasional bumps to 30-40%. I think it's running @400Hz for each color (RGB), so that's a total of 1200Hz. Not completely PWM/flicker free, but pretty close. This is just a guess from what I see in front of me. I think the same can be said for the older PremierColor panels. The new ones (4K) and any other nonDreamColor/PremierColor panels has to be examined individually.

BTW RetroPCMania is a Bulgarian site. Laptop.bg include PWM test in their newer reviews, so you might want to check them out.

Do note, just because I'm not aware if there are PWM free models, it doesn't mean that there are none, it just means that I hate 16:9, and I haven't checked anything newer than 8740w, unless by pure curiosity, so again, feel free to browse the reviews in the above two sites, and might find one that suits you. Best of luck!

 

The inspiron seems to have a lack of observed PWM flicker from this review.

http://www.notebookcheck.net/Dell-Inspiron-15-7559-Notebook-Review.154635.0.html

Also there is this website that has started tracking PWM related information for various laptops.

http://laptopmedia.com/top-laptop-pwm-ranking-rated-by-negative-impact-on-eyesight/

Their reviews are pretty thorough as far as testing the displays go.

 

The second is the translated version of laptop.bg which I mentioned, so yes keep an eye on their reviews for PWM-free options.