Gaming: response time and input lag
The Samsung C49HG90 is a gaming monitor first and foremost, as we stated before. That makes this page important: how fast is this monitor in practice?
With gaming monitors we often show the rise and fall times separately, as well as the combined values. We also show the maximum and optimal overdrive results. The optimal overdrive values are combined rise / fall response times of 16 ms or lower with an overshoot that is as low as possible. In other words: a response time of 4 ms and an overshoot of 60% is in our opinion worse than a response time of 15 ms combined with an overshoot of 5%. After all, overshoot and undershoot result in annoying artefacts around moving parts of the image, mainly with contrast-rich gradients you can see thick white or black edges. In our opinion, these are worse than light ghosting.
With non-gaming monitors we only show the combined rise- and fall-times in the standard mode and with optimal overdrive-settings: on the products pages you can always find all sub- and detail measurements.
The C49HG90 provides us with a challenge, as the FG70-series did last year: with activated overdrive it is impossible for our photo sensor, paired with the LeCroy Waverunner 6100 oscilloscope, to distinguish the changing in the image signal from the flickering of the backlight. In overdrive-mode we see that the brightness decreases a lot. We sent Samsung a question about this, but have not yet received an answer. Fortunately it does not matter a lot, because as with the FG70-series the response times are already great without overdrive. With a longest measured transition of 5.2 ms the necessary speed for 144 Hz is easily achieved.
Response times standard
Response times optimal
Taking a look at the input lag, we do not manage to get a usable, reproducible result: the scaler interferes here. If we use the old school way and compare it with a CRT-monitor using the camera-images, we see an average input lag of 16 ms. This is presumably caused by the necessity to analyze the image and have the local dimming backlight move with the shown image, but does disqualify the monitor for the most fanatical players of twitch shooters. For racing games and flight sims the chance that this minimal amount of input lag is considered as inconvenient is small - with 144Hz it is the same as slightly more than a delay of 2 frames.