The Grumpy Editor's GNOME 3 experience [LWN.net]

The Grumpy Editor's GNOME 3 experience

Posted Mar 16, 2011 13:20 UTC (Wed) by anselm (subscriber, #2796)
In reply to: The Grumpy Editor's GNOME 3 experience by jcm
Parent article: The Grumpy Editor's GNOME 3 experience

The problem with this is that current graphics cards generally no longer accelerate 2D graphics in hardware. All modern OSes (except Linux) use 3D primitives even for their desktop drawing (as opposed to »real« 3D stuff such as games) already, anyway, so there is no point for graphics card manufactures to actually go to the trouble of including accelerated 2D graphics, and a reasonable incentive to leave out stuff that will just clutter up the chip while it isn't even being used.

So, from the point of view of a Linux desktop environment developer, it's either stay with 2D drawing even if it is unaccelerated and you need to jump through hoops to do it at all, or else move over to 3D primitives for desktop drawing, which will be accelerated even though the desktop doesn't actually »look« 3D. Since using the accelerated 3D primitives enables all sorts of other cool and indispensable things that 2D drawing doesn't give one (like a bunch of virtual desktops on the faces of a cube with video playback windows hanging across the edges), this decision is mostly a no-brainer.

As for the lost basic functionality, that's a different kettle of fish altogether which is nothing to do with 2D vs. 3D. If the GNOME developers, in the process of upgrading their software offerings, want to provide us with a radically changed (I'm deliberately not saying improved or worsened – as a KDE user I wouldn't know) user experience then that is their privilege. Users can always vote with their feet.

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The Grumpy Editor's GNOME 3 experience

Posted Mar 16, 2011 15:35 UTC (Wed) by paulj (subscriber, #341) [Link] (4 responses)

2D still tends to use less power than 3D desktop though. Which means it's certainly still being implemented efficiently in hardware.

But hey, who wants longer battery hardware? Look at the shiny...

The Grumpy Editor's GNOME 3 experience

Posted Mar 16, 2011 15:46 UTC (Wed) by me@jasonclinton.com (subscriber, #52701) [Link] (3 responses)

That's not true. When Clutter is rendering animations, it actively throttles itself to avoid drawing faster than the VSync rate of the monitor to save power and avoid visual tearing. When Clutter is idle, the graphics hardware is completely idle. So since we're avoiding CPU-intensive expose events with a compositor, you actually likely have a net power savings, at least with Intel graphics. AMD and NVidia haven't yet managed to idle low enough and so they are frequently tied to an Intel graphics implementation. On proprietary OS's, if a game is not running, the Intel graphics are used. (We cannot do this in Linux, yet. Though it is on the horizon.)

The Grumpy Editor's GNOME 3 experience

Posted Mar 16, 2011 15:54 UTC (Wed) by paulj (subscriber, #341) [Link] (2 responses)

Compiz with GNOME2 certainly used more power than normal metacity on my intel graphics laptop. I'm glad to hear that clutter tries to make efficient use of the hardware.

For the sake of clarity, are you saying that clutter ought to be more energy efficient than 2D metacity on modern hardware generally? That seems to be the implication given you're contradicting my comment.

Re dual-graphics and switching, I thought airlied has got that working?

The Grumpy Editor's GNOME 3 experience

Posted Mar 16, 2011 15:59 UTC (Wed) by me@jasonclinton.com (subscriber, #52701) [Link] (1 responses)

> For the sake of clarity, are you saying that clutter ought to be more energy efficient than 2D metacity on modern hardware generally? That seems to be the implication given you're contradicting my comment.

Yes, that is what you should find. It's likely to be very close but a good test is a bunch of open windows and then dragging one window around the desktop rapidly.

> Re dual-graphics and switching, I thought airlied has got that working?

Mm... I thought I was up to date on this but perhaps you know more than I do. My understanding until now has been that dynamic graphics switching requires the same Gallium state tracker in both drivers since the entire hardware state has to be moved from one graphics card to the other. Perhaps this is the milestone that has been reached to which you are referring?

The Grumpy Editor's GNOME 3 experience

Posted Mar 16, 2011 20:03 UTC (Wed) by airlied (subscriber, #9104) [Link]

I've only got login/out switch working,

dynamic switching where it powers up/down the second GPU for running games is something I'm playing with now.

Complete switch at runtime for all X apps is also on the list but harder.