5 ms·

The transatlantic ping is waves traveling at the speed of light in fiber and a large fraction of the speed of light in copper. To send a pixel to a screen you n

The transatlantic ping is waves traveling at the speed of light in fiber and a large fraction of the speed of light in copper. To send a pixel to a screen you need to wait for the next vsync if you're not using a variable refresh rate display. That alone can be double digit milliseconds. Then you need to wait for the crystals in the screen to physically move in response to applied voltage. Moving things is slow. Moving things happens at speeds far less than the speed of light unless you're putting in enough energy to vaporize a city. If you wait around and rely on things that move extremely slowly compared to the light speed of fiber and near light speed of electrical signals, waiting around for a crystal to turn and align itself to a voltage is going to take an eternity in comparison. So yeah, no shit it's slower to display a pixel.

mdoms 5y ago
Perhaps you should read the linked Q&A before commenting.
- charliebreslau 5y ago
  Wrong. Copper is almost same speed as fiber (~200.000 km/s). Radio signal is fastest ~300.000 km/s. Light travels in fiberglass at 2/3 speed of light (precisely c - speed of light in vacuum - ~300.000 km/s. Same with twisted copper cables.
klmr 5y ago
I dunno, I don’t think it’s that obvious: the physical movement in an LCD is across tiny masses and distances (at molecular scale); the network signal has to cross a distance that’s many orders of magnitude larger. Comparing these two things without looking at actual number doesn’t strike me as valid, even for approximations. Furthermore, if I’m reading the RTINGS.com source posted below correctly, modern LCDs have smaller latencies than a transatlantic ping. So not only is it not obvious, it’s no longer universally true.
cozzyd 5y ago
Well the effective refractive index of fiber is something like 1.4 or so I think.
marginalia_nu 5y ago
That's only half the story. If you compare a PAL NES game, which runs at a fixed 50 FPS, to a modern video game that runs at 50 FPS, the former is incredibly snappy whereas the latter would be deemed unplayable sluggish. The NES signal is analog and if you update the video memory, it more than likely shows up on the screen the next frame, the worst possible delay is 20 milliseconds. Digital displays and (hardware) pipeline-based rendering means that it in practice often takes takes several frames between sending the instructions to draw mario and the little guy showing up on the screen. It still takes less than 20 milliseconds to render, but the latency is much higher. In practice a latency of 100 ms isn't unheard of at 50 FPS with a modern rendering pipeline. This is why modern games feel so sluggish at low framerates.

mdoms 5y ago

Perhaps you should read the linked Q&A before commenting.

charliebreslau 5y ago
Wrong. Copper is almost same speed as fiber (~200.000 km/s). Radio signal is fastest ~300.000 km/s. Light travels in fiberglass at 2/3 speed of light (precisely c - speed of light in vacuum - ~300.000 km/s. Same with twisted copper cables.

klmr 5y ago

I dunno, I don’t think it’s that obvious: the physical movement in an LCD is across tiny masses and distances (at molecular scale); the network signal has to cross a distance that’s many orders of magnitude larger. Comparing these two things without looking at actual number doesn’t strike me as valid, even for approximations. Furthermore, if I’m reading the RTINGS.com source posted below correctly, modern LCDs have smaller latencies than a transatlantic ping. So not only is it not obvious, it’s no longer universally true.

cozzyd 5y ago

Well the effective refractive index of fiber is something like 1.4 or so I think.

marginalia_nu 5y ago

That's only half the story. If you compare a PAL NES game, which runs at a fixed 50 FPS, to a modern video game that runs at 50 FPS, the former is incredibly snappy whereas the latter would be deemed unplayable sluggish. The NES signal is analog and if you update the video memory, it more than likely shows up on the screen the next frame, the worst possible delay is 20 milliseconds. Digital displays and (hardware) pipeline-based rendering means that it in practice often takes takes several frames between sending the instructions to draw mario and the little guy showing up on the screen. It still takes less than 20 milliseconds to render, but the latency is much higher. In practice a latency of 100 ms isn't unheard of at 50 FPS with a modern rendering pipeline. This is why modern games feel so sluggish at low framerates.