The HP 25f, 24 Envy and 25" & 27" CW/er/es/XW monitors can all be considered delay free (<3ms top screen Leo Bodnar measurement), but this is not surprising since most 1080p monitors are. 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. The actual signal delay (input lag without including the pixel response times) is likely around a millisecond, but an oscilloscope which I do not own, is required to obtain the "true" value.