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Comment by nsxwolf

5 years ago

But the text isn't making it from your keyboard through the machine and to the monitor any faster. Seems like at 120hz you're just maybe going to catch it a frame earlier when it shows up.

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nsxwolf

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formerly_proven  5 years ago

It is, because there may be multiple things synchronizing their inputs and outputs to the refresh, which causes the refresh-related latency to be a number of frames. E.g. in some Linux compositors inputs are latched with the refresh, apps themselves may render in sync, and the compositor also draws in sync; the GPU driver would also introduce at least a frame of latency typically.

Another factor is that some (many?) 60 Hz displays buffer a whole frame themselves, and often don't have quick response times. If you go from a 10 ms response time IPS screen with a frame buffer to a 120 Hz gaming screen with 2-3 ms response time, you already got a difference of about 25 ms just in the screen itself.

8 ms is hard to notice. 50 ms less so.

The difference is pretty huge, even on systems that are much better tuned than Linux desktops (e.g. Windows 10).

That being said, while it is very nice and feels nice, it's not necessary for development work; I spend most of my days developing on a system over a VNC connection through a VPN, so the basic input lag of that setup is around 200-300 ms. Gnarly yes, but not particularly bad for text input. You get used to just do everything very slowly with the mouse.

  • 1996  5 years ago

    > The difference is pretty huge, even on systems that are much better tuned than Linux desktops (e.g. Windows 10).

    What would you suggest, or either Windows 10 or Linux, to get the lowest latency in a terminal?

    • toast0  5 years ago

      If you want the lowest latency in a terminal, use a vga textmode console with a ps/2 keyboard. That's pretty hard to get on windows 10, so I'd go with Linux.

      2 replies →

hmage  5 years ago

In the article: > We get a 90 ms improvement from going from 24 Hz to 165 Hz.

As per the linked article, the observed delay improvement isn't one frame, more like ~3 frames. It doesn't go up from 1/24 to 1/165, it goes from 2.5/24 to 2.5/165.

Computer software waits a lot more than it did in 1977. That's why 240hz displays feel much more snappier even if it's supposed to be less noticeable -- you're waiting for same 3 frames, but they pass by much faster.

Jonnax  5 years ago

I guess so, the difference between 8ms vs 16ms is not much for 1 frame.

Though in my totally subjective experience it feels better.

Interestingly the person who did this latency test also did a keyboard latency test:

https://danluu.com/keyboard-latency/

Compared to the slowest keyboard measured it's possible to shave 45ms which if you were latency sensitive would be the biggest reduction.

  • dsissitka  5 years ago

    > A major source of latency is key travel time. It’s not a coincidence that the quickest keyboard measured also has the shortest key travel distance by a large margin. ... Note that, unlike the other measurement I was able to find online, this measurement was from the start of the keypress instead of the switch activation.

    That's disappointing. He isn't measuring latency nearly as much as he's measuring point of actuation.