The Dell S2719DGF can be considered delay free (<3.5ms top screen Leo Bodnar measurement), but this is not surprising since most TN panels are, especially gaming oriented TN panels. Usually only multi-input 1440p-4k monitors have a around a frame (16.7ms) or two (33.33ms) of input lag. The Leo Bodnar device measures 9.8ms in the middle of the screen, but the Bodnar device has a built in delay and partially includes the monitors black-to-white pixel response times. Top screen Bodnar results are in the 3ms range. The actual signal delay (input lag without including the pixel response times) is likely less than a millisecond, but an oscilloscope is required to obtain the "true" value.