Take caution: Samsung Galaxy Note 9 display flickers by design and could cause eyestrain
The Galaxy Note 9 has become the top Android smartphone of 2018 thus far with universal praise from reviewers left and right. Samsung arguably has the best mobile displays in the market and the Note 9 is just the latest example in a long line of photogenic flagships.
As attractive as the Galaxy Note 9 display may be, it unfortunately suffers from a characteristic that most smartphones do not: pulse-width modulation or PWM for short. The Samsung smartphone utilizes PWM for brightness control and so the display will flicker by design when on lower brightness settings. Depending on the frequency of the flickering, sensitive users may experience eyestrain or tiredness when looking at the screen for extended periods. The practice is generally more common on laptops such as on some Lenovo ThinkPad models.
In the case of the Galaxy Note 9, we are able to record a low flickering frequency of 227 Hz when the brightness setting is not at maximum. Most users are not sensitive to onscreen flickering and will not have to worry, but users who are sensitive to the phenomenon should take caution as low flickering frequencies tend to be more impactful.
As another example of smartphone PWM, owners of the OnePlus 6 were reporting similar flickering issues back in July. Our own tests have shown that the OnePlus 6 display does indeed flicker at 236 Hz - very close to what we've recorded on the Galaxy Note 9 - and could potentially cause eyestrain to sensitive users as well.