XGL and AIGLX...

[stjepan]

I always wondered about what's the real difference between AIGLX and XGL and which one should I use. Everybody says AIGLX is better and it's "the future".
Then I just emailed David and got the answer:

XGL got a more efficient implementation of GLX_EXT_tfp, it can
accelerate redirected GLX applications and XVideo.

XGL is a completely new X server acceleration architecture that uses
OpenGL.

AIGLX is not an acceleration architecture, it's just an extension to the
existing Xorg server with the old acceleration architecture called XAA.
So XGL and AIGLX are very different things. AIGLX just implements
accelerated indirect rendering and GLX_EXT_tfp, which are sort of built
into the acceleration architecture in the case of XGL.

AIGLX is nice as it's a small incremental change which can be used with
the current acceleration architecture and provides support for running a
compositing manager like compiz. XGL is about much more than this but I
don't have time to go into details about why I believe XGL is the
acceleration architecture for the future.

stjepan

[mikedee]

XGL is about much more than this but I
don't have time to go into details about why I believe XGL is the
acceleration architecture for the future.

This sounds interesting, I must admit I was always led to believe that Xgl was a temporary solution. My only memories of it were massive memory usage and 2 servers running.

I am sure he will be explaining the benefits of Xgl in the form of compilable C code :)

[Amaranth]

XGL uses OpenGL for all X operations. In that sense it's like OS X's Quartz 2D Extreme, which is a sort of Holy Grail for Mac users since it's really buggy and hard to even turn on. AIGLX let's video drivers selectively choose to implement X operations in OpenGL when and where it would actually be worth doing.


So, basically, XGL is a complete new X server running on GL, AIGLX is an extension to Xorg that lets drivers mix X and GL together.

[amgeex]

I always have wandered why we have to run XGL along with another X server. If XGL is an X server on its own, with OpenGL acceleration built-in, why does it need another server? :shock:

[stjepan]

No, you don't need it. Right now I'm using bare Xgl. I just let GDM use it...

[iznogood]

So what is best???
I use AIGLX and works great but if XGL has improved maybe i should switch to it ???

Also i thing that XGL was another step towards Xegl (some of the code at least) and maybe things are moving slowly to that direction???I say this due to the fact that XGL can work now as a standalone server... This was not the case before

[iznogood]

How do you configure XGL to run as standalone???
Is it the same as before ??

[jesper]

I wouldn't know... I switched to Open Source ATI R300 drivers (it's great fun compiling GIT xserver and hacking synaptics drivers to work with it), but they didn't run Compiz to well using AIGLX. Now I'm back on plane old kwin, that's much faster then Compiz on XGL or AIGLX and runs all my scientific Motif/Java apps (Pro/E, Maple 10, Matlab) and Openoffice without bugs.

Although I like to switch to compiz again when things stabilize, I think pretty soon (Xorg 7.2 or 7.3 release I hope)

[Amaranth]

XGL cannot run standalone, if you start it without Xorg it'll start Xorg for you. Last time I checked it still had all the same problems with 3D apps and videos barely working if at all.

[delphinen]

Personally, I would say that XGL is at the moment, the better and most technologically modern way to accelerate X.
AIGLX is not that good in my opinion, and Nvidia direct rendering, while works nice, its not as smooth as XGL.
Basically, if you want the best graphics quality at the moment, you want everything to be rendered with OpenGL, so you should use XGL; if you want compatiblity because you want to use direct rendering, like playing Quake III on a windows with Compiz running, you should go for Nvidia's direct rendering. If that doesnt work, you still have AIGLX.