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I don't think this is actually true. If you're looking at a static page that doesn't change in any way, isn't the browser completely idle? Edit: To clarify, I

I don't think this is actually true. If you're looking at a static page that doesn't change in any way, isn't the browser completely idle? Edit: To clarify, I realize that the screen gets refreshed ~60 times per second (depending on refresh rate), but I don't think any rendering actually happens if it doesn't need to.

s_ngularity 9y ago
The GPU is drawing 60 times a second regardless of whether the page is static. Not sure how they do their streaming to the GPU, but there will be state changes every time you scroll, or click a button, etc., even on a static page.
- TickleSteve 9y ago
  no, the GPU is refreshing the video output at 60Hz, the graphics are not being redrawn at 60Hz in your typical GUI application. Games are a special case of course.
- pohl 9y ago
  The specs for my mobile GPU say that it has 1024 cores. Wouldn't it be surprising if they were all fully active regardless of workload? (It seems like low-hanging fruit for making a laptop GPU energy efficient.)
- rayiner 9y ago
  There is a difference between drawing the frame into the frame buffer, and scanning the frame buffer out to the display. If you application is coded at all sanely, only the latter is happening at 60 Hz with a static page.
ricardobeat 9y ago
The GPU is still painting the screen at a set refresh rate (your monitor’s). Some monitors have variable refresh rates, but don’t go any lower than 30hz, and depending on settings like vsync the gpu might still be churning through hundreds of wasted frames. The latest iPads can go down to 24hz to save energy due to their custom 120hz display, but that’s a rarity.
- vvanders 9y ago
  It depends on the GPU arch. Some of them use a separate 2D compositor that uses much less power so if you're just scrolling layers you aren't lighting up the full GPU.
- vetinari 9y ago
  In this case, the GPU just sends the content of the framebuffer to the screen. It does not re-render the content of the framebuffer, which is what the most energy is usually spent on.
  - jug 9y ago
    Also I imagine that particular path of simply sending the framebuffer is a highly optimized one.
- zlynx 9y ago
  Intel GPUs support Panel Self Refresh. Tablet and laptop panels can go very slow. Less than 24 FPS, for sure! It is whatever the low end is on their LCD controller (they forget over time, like DRAM). This article has some diagrams and explanations: http://www.hardwaresecrets.com/introducing-the-panel-self-refresh-technology/2/ http://www.hardwaresecrets.com/introducing-the-panel-self-re...
- deleted 9y ago
  [deleted]
- nicalsilva 9y ago
  Let's clarify, WebRender doesn't do anything at all if nothing changed. If the content of the window is static then webrender won't wake your gpu up until it really needs to. There seem to be a confusion about video games needing to render at constant frame rate, but that is only the case in games where there is always something changing on screen. It isn't that uncommon for other types of games with more static graphics to not render if nothing has changed.
  - Dylan16807 9y ago

s_ngularity 9y ago

The GPU is drawing 60 times a second regardless of whether the page is static. Not sure how they do their streaming to the GPU, but there will be state changes every time you scroll, or click a button, etc., even on a static page.

TickleSteve 9y ago
no, the GPU is refreshing the video output at 60Hz, the graphics are not being redrawn at 60Hz in your typical GUI application. Games are a special case of course.
pohl 9y ago
The specs for my mobile GPU say that it has 1024 cores. Wouldn't it be surprising if they were all fully active regardless of workload? (It seems like low-hanging fruit for making a laptop GPU energy efficient.)
rayiner 9y ago
There is a difference between drawing the frame into the frame buffer, and scanning the frame buffer out to the display. If you application is coded at all sanely, only the latter is happening at 60 Hz with a static page.

ricardobeat 9y ago

The GPU is still painting the screen at a set refresh rate (your monitor’s). Some monitors have variable refresh rates, but don’t go any lower than 30hz, and depending on settings like vsync the gpu might still be churning through hundreds of wasted frames. The latest iPads can go down to 24hz to save energy due to their custom 120hz display, but that’s a rarity.

vvanders 9y ago
It depends on the GPU arch. Some of them use a separate 2D compositor that uses much less power so if you're just scrolling layers you aren't lighting up the full GPU.
vetinari 9y ago
In this case, the GPU just sends the content of the framebuffer to the screen. It does not re-render the content of the framebuffer, which is what the most energy is usually spent on.
- jug 9y ago
  Also I imagine that particular path of simply sending the framebuffer is a highly optimized one.
zlynx 9y ago
Intel GPUs support Panel Self Refresh. Tablet and laptop panels can go very slow. Less than 24 FPS, for sure! It is whatever the low end is on their LCD controller (they forget over time, like DRAM). This article has some diagrams and explanations: http://www.hardwaresecrets.com/introducing-the-panel-self-refresh-technology/2/ http://www.hardwaresecrets.com/introducing-the-panel-self-re...
deleted 9y ago
[deleted]
nicalsilva 9y ago
Let's clarify, WebRender doesn't do anything at all if nothing changed. If the content of the window is static then webrender won't wake your gpu up until it really needs to. There seem to be a confusion about video games needing to render at constant frame rate, but that is only the case in games where there is always something changing on screen. It isn't that uncommon for other types of games with more static graphics to not render if nothing has changed.
- Dylan16807 9y ago