Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Transatlantic ping faster than sending a pixel to the screen? (2012)

superuser.com

Post reply on HN
Print view View original

21–30 of 31 posts

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#21

Post by cozzyd »

retrac wrote: post #15
ksec wrote: post #8

I have always been crying about latency computing for years. My earliest HN comment on the topic was in 2012. And I have been ranting about it for even longer outside I really hope at the later part of this decade we start focusing on latency computing instead of bandwidth. From Display, Input, Output and Network, and down to OS and Software. I had always hoped VR would forced those optimisation due to VR being a lat…

To me, the threshold of cringing is when web forms are laggy. This 50-billion-instructions-per-second box can be slower rendering an input form than a VT220 terminal from 1983. When the task of the machine is to, e.g. enter appointment booking information, and it handles the task worse than hardware from decades ago could in some cases, that's when we know we've lost the plot.

Yes, or, even more annoyingly, when slack lags as you type. I think I've had ssh connections to the south pole with less latency than slack sometimes has.

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#22

Post by cozzyd »

Veliladon wrote: post #10

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. Movi…

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

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#23

Post by ksec »

retrac wrote: post #15
ksec wrote: post #8

I have always been crying about latency computing for years. My earliest HN comment on the topic was in 2012. And I have been ranting about it for even longer outside I really hope at the later part of this decade we start focusing on latency computing instead of bandwidth. From Display, Input, Output and Network, and down to OS and Software. I had always hoped VR would forced those optimisation due to VR being a lat…

To me, the threshold of cringing is when web forms are laggy. This 50-billion-instructions-per-second box can be slower rendering an input form than a VT220 terminal from 1983. When the task of the machine is to, e.g. enter appointment booking information, and it handles the task worse than hardware from decades ago could in some cases, that's when we know we've lost the plot.

>To me, the threshold of cringing is when web forms are laggy.

Same here that was what ticked me. I was reading up HN threads I saved and the Remix framework was one of them. People were cheering for a well design, animated and smooth webpage. Because most of the other similar design tends to Jank and not smooth. We are coming to 2022, rendering a webpage on modern CPU with GPU accelerated browser should be trivial. And yet that web page was, true to most comments and my experience, an outliner.

A lot of people continue to say those latency doesn't matter. It does. I am picky, I hate latency. I am latency sensitive. I can only wish some day ( again may be VR or Metaverse ) we could kick start latency computing. Or Real Time computing.

"To make Metaverse, we need Real Time Computing" seems like a good message to VC and consumer market :)

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#24

Post by Aerroon »

retrac wrote: post #15
ksec wrote: post #8

I have always been crying about latency computing for years. My earliest HN comment on the topic was in 2012. And I have been ranting about it for even longer outside I really hope at the later part of this decade we start focusing on latency computing instead of bandwidth. From Display, Input, Output and Network, and down to OS and Software. I had always hoped VR would forced those optimisation due to VR being a lat…

To me, the threshold of cringing is when web forms are laggy. This 50-billion-instructions-per-second box can be slower rendering an input form than a VT220 terminal from 1983. When the task of the machine is to, e.g. enter appointment booking information, and it handles the task worse than hardware from decades ago could in some cases, that's when we know we've lost the plot.

A big performance problem is live autocomplete on your input. The website running some kind of a query on every character you input sometimes causes huge delays. On my phone I can sometimes wait a good 5-10 seconds after I finished typing for it to actually show up on screen.

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#25

Post by SV_BubbleTime »

emteycz wrote: post #17
hhhhhklkkliiii wrote: post #14

Earlier quoted context omitted.

VR never happened? Someone needs to let Valve and Oculus know..

Well it certainly did not happen in way other technologies happened - smartphones, social networks, laptops, desktops... VR is definitely slower and smaller market right now than these other devices were after similar number of years.

I’m ok with VR being slow. There is no need to rush it. There are some amazing VR experiences. Half Life Alyx while standing, despite it being a disaster overall VirtaMate can have some really interesting erotic setups, beat saber is the only music game I’ve ever really got into, and… IDK, some things are just not possible outside of VR like SuperHot VR being a totally different everything than it’s normal version.

I would like there to be more quality content but sooner, but I think it’s largely in a grey area between hardware not being good enough yet and software being expensive to develop.

I used to poopoo it, but I’ve come around that VR is in the cards, just slowly.

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#26

Post by SV_BubbleTime »

clktmr wrote: post #9

Optimizing for latency is often counter-intuitive. Polling as an example may be an effective way to lower latency, e.g. Linux NAPI. Increasing buffer sizes may also decrease latency because data can be processed in bursts, see buffer starvation. But if data comes in at a higher rate than can be processed, buffers fill up and are horrible for latency.

> Polling as an example may be an effective way to lower latency,

I had to learn this lesson the hard way recently.

An embedded system where I had to get data from a couple SPI controller’s RAM. Made a bit complicated ISR and listener system that woke up threads to do a deferred-interrupt… by the time it was all said and done with a fair bit of code, I wasn’t happy with it.

I figured out that usually data would be available every 2ms and just wrote the read routine just to sleep every 2ms and attempt another read, I have it “hitting” 90% of the time and my avg latency is almost nothing. .7ms or so.

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#27

Post by marginalia_nu »

Veliladon wrote: post #10

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. Movi…

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.

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#28

Post by Schroedingersat »

retrac wrote: post #15
ksec wrote: post #8

I have always been crying about latency computing for years. My earliest HN comment on the topic was in 2012. And I have been ranting about it for even longer outside I really hope at the later part of this decade we start focusing on latency computing instead of bandwidth. From Display, Input, Output and Network, and down to OS and Software. I had always hoped VR would forced those optimisation due to VR being a lat…

To me, the threshold of cringing is when web forms are laggy. This 50-billion-instructions-per-second box can be slower rendering an input form than a VT220 terminal from 1983. When the task of the machine is to, e.g. enter appointment booking information, and it handles the task worse than hardware from decades ago could in some cases, that's when we know we've lost the plot.

Even worse is text fields that cannot keep up with typing even on a brand new processor.

I haven't used facebook messenger in yearw, but last time I did, typing was at leas O(n^2) and would bring any cpu to its knees if messages were typically 100s of words.

Gumtree is another (doesn't register characters if you type them to fast). Probably the exact same code as they were acquired by facebook.

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#29

Post by IshKebab »

emteycz wrote: post #17
hhhhhklkkliiii wrote: post #14

Earlier quoted context omitted.

VR never happened? Someone needs to let Valve and Oculus know..

Well it certainly did not happen in way other technologies happened - smartphones, social networks, laptops, desktops... VR is definitely slower and smaller market right now than these other devices were after similar number of years.

By that metric almost nothing "happened".

And I'd say VR is advancing way faster than desktops, and maybe even the rest of your list. You just don't remember the products that existed when they were still fairly niche, like the iPaq, Amstrad and Friendster.

Re: Transatlantic ping faster than sending a pixel to the screen? (2012)

#30

Post by charliebreslau »

mdoms wrote: post #12
Veliladon wrote: post #10

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. Movi…

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

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.

Post reply on HN