PWM vs Non PWM?

[Gaming_Addiction]

Well, A LOT of people camplain about monitors having PWM controlled backlight. Some people say blues, reds, and grays look horrible with it and get headaches an also flickering. I need to get a new monitor now (Long story) and deciding on monitors. 1440P is way to hard to run so I am staying around 1200p.

 

I am looking at the PA248Q

 

Will I notice PWM?

How hard do I have to look to notice the flickering?

How do I know if I am sensitive to flickering?

How can it give headaches?

If you advise me to go against PWM, can you recomend me a good IPS, 23"-24", and 1200p monitor?

 

 

[Butterfish]

I got the PB278Q from ASUS, and it supposed to have PWM backlight. but honestly i never had any problem with it. I read that i will give headaches when gaming, so ofc i got a bit woozie at the start, but i soon realized it was just placebo. I have now used it for more than half a year and i dont have any problem with headaches and what not

[helping]

http://linustechtips.com/main/topic/49601-are-you-pwm-sensitive/

[Emperor_Piehead]

Your monitor most likely uses PWM so you would have noticed it. All monitors use PWM, but some monitors use W-led tech to remove the flickering. The only one I know of that uses w-led is the U2413. You would be fine with a standard backlight if you don't have an issue with your current one. 

 

I would just stick with PA248Q

 

The colors look different thing is also BS since it wouldn't affect colors.

[bradscoolio]

I can't really answer your question with great experience but given I use lightboost mod on my monitor which is a form pwming backlight, it doesn't really make it flicker persay but I can see thin lines horizontally across my screen just like CRT monitors did.

[GoodBytes]

The ASUS PA248Q uses a PWM at only 180Hz for 50% brightness... this is the worst you can get. Meaning you'll feel the flickering, especially at lower brightness. It's just awful.

The Dell U2413 uses a PWM but ONLY if the brightness is bellow 20% AND that is with a speed of 8750Hz, this is so fast, I highly doubt you'll notice a thing. Any brightness level above 20% you have no PWM, and actual dimming circuit to control the LEDs. The U2413 uses GB-LED backlight, a nice kind of backlight technology, which uses Green, and Blue LED's, put very close together with a layer of red phosphor on top, to output a white light. This allows allows the monitor to have a better white, compared to white LEDs (the normal LED back light  technology), which output a very cold white which affects colors.

 

Emperor_piehead is incorrect on some points.

 -> Backlight color DOES affect the colors of the screen big time.

 -> White LED monitors DO NOT have to use a PWM to be controlled. Proof: Dell P2314T and P2414T as examples (both are 1080p IPS panels, if you wonder), among many others on the market.

 -> "W-LED" means white LED, contrary to GB-LED, which is what I explained above, and RGB-LED, where you have red, green and blue LED's put very close together to output a white light (this is still expensive, and only found on select professional grade monitors).

 -> I would avoid the PA248Q at all costs.

[mdrejhon]

Some monitor makers vary the PWM frequency in firmware updates, to try to reduce PWM issues.

 

 

I just got a new Asus VG248QE (manufactured in June 2013) and was positively surprised to measure a PWM frequency of 864Hz.

 

For example, the early VG248QE's came with 432Hz PWM during 144Hz mode, but they've bumped that up to 864Hz PWM during 144Hz, via improved firmware as I understand it.   Still not high enough IMHO, although I wonder if the G-SYNC upgrade boards will do anything to raise the PWM frequency (in non-strobed mode). Among the 120Hz world, the XL2420TE (And XL2420T Rev 2.0) are the only true 120Hz monitors that are PWM-free at the moment, where XL2420T Rev 1.0 definitely has PWM.

 

Moral of the story -- even the same-model monitor sometimes have different PWM frequencies, or revision 2.0 goes PWM-free.  In certain cases, pay careful attention to revision numbers too!