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Transatlantic ping faster than sending a pixel to the screen?

I can send an IP packet to Europe faster than I can send a pixel to the screen. How f’d up is that?

And if this weren’t John Carmack, I’d file it under “the interwebs being silly”.

But this is John Carmack.

How can this be true?

To avoid discussions about what exactly is meant in the tweet, this is what I would like to get answered:

How long does it take, in the best case, to get a single IP packet sent from a server in the US to somewhere in Europe, measuring from the time that a software triggers the packet, to the point that it’s received by software above driver level?

How long does it take, in the best case, for a pixel to be displayed on the screen, measured from the point where a software above driver level changes that pixel’s value?

3 Answers

So, at 30FPS we get baseline performance of eight frames/133ms, but in the second clip where the game has dropped to 24FPS, there is a clear 12 frames/200ms delay between me pulling the trigger, and Niko beginning the shotgun firing animation. That's 200ms plus the additional delay from your screen. Ouch.

A Display can add another 5-10ms

So, a console can have upto 210ms of lag

And, as per David's comment the best case should be about 70ms for sending a packet
It is very simple to demonstrate input lag on monitors, just stick an lcd next to a crt and show a clock or an animation filling the screen and record it. One can be a second or more behind. It is something that LCD manufacturers have tightened up on since gamers, etc have noticed it more.
Your USB trigger is probably running as a Low speed USB device (bus frames at 125usec) causing a minimal 8ms delay (hardware issue). Maybe try a PS2 keyboard instead ?

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