XPS 15 OLED, PWM (pulse width modulation)

Please consider PWM (pulse width modulation) before buying XPS 15 OLED version. PWM describes a flickering of the background illumination to reduce the luminance. Sensitive users may see this flickering below a certain frequency and get tired eyes or headaches. These problems might not even be obvious. More than 500 Hz are generally not an issue, but there seem to be many users with problems below 250 Hz. Beware, there are even reports from readers that suffer from frequencies above 10k Hz. These users should look at the individual reviews and look out for completely flat lines in our measurements as small brightness changes may lead to sore eyes, headache. See here and here.