Rasmus Larsen wrote:I noticed it when moving from side to side, but only on the darker grey colors in tweetdeck. Besides that I didn't really notice it when just sitting at my chair. But I can imagine that it could be a problem when using two FG2421 monitors in a multi-screen setup.
Ahh thank you. If it's only on darkest colors and you see no variations on bright ones (esp. white which is very present in web browsing) then it is all good for me !!
Rasmus Larsen wrote:I don't think it was noticeable during gaming, no, but it was not zero in measurements. I'm guessing that the 240 Hz involves a little bit of processing that adds a few ms of input lag.
The manual explains how the turbo works:
step1: screen is refereshed with heavy overdrive and backlight off
step2: next frame, screen is refreshed with the same image with no overdrive and backlight still off
step3: when image is set at some time of step 2, backlight is lit (short strobe)
Given the above we can say turbo adds at least 4.2ms delay vs turbo off as the image is not shown at the 1st refresh but only the 2nd one (with 240hz refresh). As backlight is lit somewhere within the 2nd pass (the one showing a duplicate of the previous refresh) a bit more time should again be added.
Though we don't know precisely when backlight is lit on the 2nd refresh. If it is lit for 1ms at the very end of the 2nd refresh then that would mean 3.2ms more to add (about 7ms more that without turbo in total).
But we have to consider that with turbo the image is displayed sharp as soon as it becomes visible (as it was prepared during the time backlight is off). So subjectively that should lower the added delay at bit.
Of course as you said there may certainly some processing time, but we have to consider the above additional time is added to it.