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analog vs digital signal synchronization and input lag

Posted: 13 Jun 2014, 15:20
by flood
http://www.prad.de/en/monitore/specials ... art17.html

long and technical article, but basically it finds that the vblank signals in the analog and digital outputs are not synchronized on most graphics cards; hence measuring the input lag difference between a crt monitor and an lcd monitor with the lcd monitor connected to a digital output isn't a great idea.

what I'm curious about is whether this is significant input lag in the digital-to-analog process in the graphics card. If there is, then CRT monitors may have more input lag overall than some lcd monitors.

Re: analog vs digital signal synchronization and input lag

Posted: 13 Jun 2014, 21:46
by Q83Ia7ta
flood wrote:http://www.prad.de/en/monitore/specials ... art17.html

long and technical article, but basically it finds that the vblank signals in the analog and digital outputs are not synchronized on most graphics cards; hence measuring the input lag difference between a crt monitor and an lcd monitor with the lcd monitor connected to a digital output isn't a great idea.

what I'm curious about is whether this is significant input lag in the digital-to-analog process in the graphics card. If there is, then CRT monitors may have more input lag overall than some lcd monitors.
I can tell only from my experience playing QuakeWorld at 1155fps or Quake Live at 250fps at CRT@144hz and LCD@144hz. CRT feels a bit responsible but that difference is tiny. May it's placebo caused by motion blur at LCD@144hz.

Re: analog vs digital signal synchronization and input lag

Posted: 13 Jun 2014, 23:13
by Chief Blur Buster
Q83Ia7ta wrote:May it's placebo caused by motion blur at LCD@144hz.
LCD motion blur can actually adds an input lag sensation during eye-tracking situations (e.g. tracking eyes on moving objects, like www.testufo.com ...) The trailing blurring effect is a a visual form of lagging.

However, during stationary eye situations (e.g. staring at crosshairs), the strobing benefits aren't seen, and the absolute input lag matters a whole deal more.