4 ms·

> It tries to minify latency Quiet the opposite. Tearfree rendering, forced vsync and the completely opaque way of interacting with graphics memory in order to

by sprash 5y ago

> It tries to minify latency Quiet the opposite. Tearfree rendering, forced vsync and the completely opaque way of interacting with graphics memory in order to fulfill the "every frame is perfect" philosophy means Wayland is optimized for all kinds of things (mainly to give involved consulting firms some lucrative gigs) but certainly not latency.

sandreas 5y ago
Could you give more details on that? This sounds like Wayland is not your favourite...
- sprash 5y ago
  I discussed this in past comments: https://news.ycombinator.com/item?id=29017674 https://news.ycombinator.com/item?id=29017674 https://news.ycombinator.com/item?id=29017940 https://news.ycombinator.com/item?id=29017940
  - sandreas 5y ago
    Thank you. This is something I will definetely investigate further :-)
Seirdy 5y ago
It's more nuanced than that. If your goal is to have a desktop without screen tearing, you will beed a compositor. Wayland will do better at minifying latency than an X11 compositor due to having better frame scheduling. This is especially pronounced on very low-end ARM devices like the Pinebook that experience lag on DWM but are incredibly snappy under Sway. If you are fine with visual glitches like screen tearing due to e.g. a lack of vsync then X might have less latency.
- sprash 5y ago
  > If you are fine with visual glitches There are cases where tearing is extremely distracting, like playing videos or scrolling in the browser. There are cases where tearing will not be noticed at all but low latency might be beneficial, e.g. when you only have small areas of the screen that are updated, like moving the mouse cursor or editing text. And there are cases where it is a user preference, e.g. Games (Many people play competitive FPS Games without vsync whereas scrolling without vsync in strategy games will be very distracting). The point is to give the user a choice when there is a trade-off. The trade-off here is vsync vs. low latency. Wayland makes the choice for you. On X11 each application can do what makes sense for that particular use case and on top of that the compositor can be turned off, on or even be replaced at runtime without affecting running programs. X11 is superior technology in every way if you ask me.
  - dkersten 5y ago
    From a purely practical point of view, for me personally, I have a laptop where no matter what I tried, with X I got insane constant screen tearing. I tried with and without compositors, different configuration, different drivers. Nothing worked for me. I tried wayland and its been running silky smooth without any tearing whatsoever. So, from a personal practical perspective, whatever Wayland does has worked for me, while X11's "superior technology" has completely failed me, on that laptop.
    - sprash 5y ago
      On a technical/conceptual level X11 can potentially be the best of both worlds and Wayland can't. In practice drivers and programs have bugs, sure. But that can not be blamed on X11 as protocol/API.
      - zepto 5y ago
        That’s like saying you can’t blame C for buffer overrun vulnerabilities because those are just bugs. If the system makes it easy to write buggy programs and there are common problems that take a lot of effort for developers to overcome it is a bad system.
  - Seirdy 5y ago
    X11 has no GUI isolation which in this day and age is inexcusable in a desktop operating system. The only decent attempt at proper isolation for X that I know of is Qubes, done using Xen. Furthermore, Wayland can have lower input latency than X if you are dealing with more complex input. Text nowadays has grapheme clustering, ligatures and text shaping (including runtime text shaping), and other oddities; this is a heavy task that can incur latency. Latency can be reduced by offloading some of this to the GPU. Frame timing combines well with this approach to ensure that only displayed frames get rendered, synced with display refresh. The result is dramatically lower latency when taking into account display refresh rate. In other words, Wayland's vsync support can make complex tasks like modern text input incur lower latency and use fewer resources. On Sway, for instance, if you tune the compositor with sway-input, you can actually achieve lower latency than on X11 WMs like dwm, even without a compositor. This is even more pronounced on low-end ARM machines.

by sprash 5y ago

sandreas 5y ago

Could you give more details on that? This sounds like Wayland is not your favourite...

sprash 5y ago
I discussed this in past comments: https://news.ycombinator.com/item?id=29017674 https://news.ycombinator.com/item?id=29017674 https://news.ycombinator.com/item?id=29017940 https://news.ycombinator.com/item?id=29017940
- sandreas 5y ago
  Thank you. This is something I will definetely investigate further :-)

Seirdy 5y ago

It's more nuanced than that. If your goal is to have a desktop without screen tearing, you will beed a compositor. Wayland will do better at minifying latency than an X11 compositor due to having better frame scheduling. This is especially pronounced on very low-end ARM devices like the Pinebook that experience lag on DWM but are incredibly snappy under Sway. If you are fine with visual glitches like screen tearing due to e.g. a lack of vsync then X might have less latency.

sprash 5y ago
> If you are fine with visual glitches There are cases where tearing is extremely distracting, like playing videos or scrolling in the browser. There are cases where tearing will not be noticed at all but low latency might be beneficial, e.g. when you only have small areas of the screen that are updated, like moving the mouse cursor or editing text. And there are cases where it is a user preference, e.g. Games (Many people play competitive FPS Games without vsync whereas scrolling without vsync in strategy games will be very distracting). The point is to give the user a choice when there is a trade-off. The trade-off here is vsync vs. low latency. Wayland makes the choice for you. On X11 each application can do what makes sense for that particular use case and on top of that the compositor can be turned off, on or even be replaced at runtime without affecting running programs. X11 is superior technology in every way if you ask me.
- dkersten 5y ago
  From a purely practical point of view, for me personally, I have a laptop where no matter what I tried, with X I got insane constant screen tearing. I tried with and without compositors, different configuration, different drivers. Nothing worked for me. I tried wayland and its been running silky smooth without any tearing whatsoever. So, from a personal practical perspective, whatever Wayland does has worked for me, while X11's "superior technology" has completely failed me, on that laptop.
  - sprash 5y ago
    On a technical/conceptual level X11 can potentially be the best of both worlds and Wayland can't. In practice drivers and programs have bugs, sure. But that can not be blamed on X11 as protocol/API.
    - zepto 5y ago
      That’s like saying you can’t blame C for buffer overrun vulnerabilities because those are just bugs. If the system makes it easy to write buggy programs and there are common problems that take a lot of effort for developers to overcome it is a bad system.
- Seirdy 5y ago
  X11 has no GUI isolation which in this day and age is inexcusable in a desktop operating system. The only decent attempt at proper isolation for X that I know of is Qubes, done using Xen. Furthermore, Wayland can have lower input latency than X if you are dealing with more complex input. Text nowadays has grapheme clustering, ligatures and text shaping (including runtime text shaping), and other oddities; this is a heavy task that can incur latency. Latency can be reduced by offloading some of this to the GPU. Frame timing combines well with this approach to ensure that only displayed frames get rendered, synced with display refresh. The result is dramatically lower latency when taking into account display refresh rate. In other words, Wayland's vsync support can make complex tasks like modern text input incur lower latency and use fewer resources. On Sway, for instance, if you tune the compositor with sway-input, you can actually achieve lower latency than on X11 WMs like dwm, even without a compositor. This is even more pronounced on low-end ARM machines.