aiglx vs xgl

[xwred1]

Right now I'm using compiz, set up as per netllama's compiz thread that is stickied here. Starting compiz without --indirect-rendering makes video and games perform a bit render, and they render more consistently on the face of the cube and stuff.

My understanding is that that configuration is called.. aiglx?

I'm also hearing that using xgl is faster, but I thought it was an unnecessary layer of indirection with the newer drivers now. Can someone explain it to me? The documentation on these things seems a bit lacking. Trying to google for it mostly just turns up various howto guides, which are short on explanations.

I'm looking into this because I might have noticed an odd problem tonight. I was running without --indirect-rendering, playing wow in cedega for several hours. After a while, compiz was weirding out a little bit. Opening new windows would have the contents just be giant black blocks, and anything trying to use xv would crash immediately. Quitting cedega made this behavior go back to normal.

Is that black box behavior maybe similar to what screws up Wow's d3d rendering in the 9xxx drivers? That still doesn't explain what kills xv, though.

[piotrq__]

I'm using beryl (compiz's fork) without XGL and it's WAY faster then it was with it. XGL was a pretty big memory eater and evertyhing was slow, especially XV and things like scrolling web pages, or with lots of flash content, not to mention the lack of direct rendering. Anyway, everything is smooth 'n sweet with these new drivers now.

This "black-windows" bug is a known ting and is caused by video memory exhaustion, it will be resolved in the future release of the driver.
What I can recommend you to use to avoid this bug is beryl (recent svn build) it has a new rendering method which does not require GLX_EXT_texture_from_pixmap extension, and one more nice thing about that is that it's as fast, or sometimes even faster than texture_from_pixmap mode.

Visit http://www.beryl-project.org/, get yourself a recent copy and enjoy!

[MacSlow]

Not using GLX_EXT_texture_from_pixmap is not very wise. This avoids sharing the memory used by a windows pixmap between X11 and GL, thus doubling memory-usage. That's the main motivation for developing this extension in the first place, to avoid this waste of video-memory. The people behind beryl don't always think thoroughly (due to lack of experience with X11?) about the stuff they do. They tend to prefer quick&dirty solutions in order to gain some questionable merits (e.g. hacking input-transformation into beryl without the proper X11-extension done by Keith Packard).

But not everything they do is bad (e.g. the animation- and blurfx-plugins are nice). Although I've to admit I know more negative than positive things.

Best regards...

MacSlow

[piotrq__]

I'd use this non-tfp hack as a temporary workaround 'till nvidia folks fix things up Mac ;-)
I know that beryl devs are not experienced software engineers, but thay are creative, smart, stubborn and they have the community of users just as stubborn as thay are, so beware compiz team! You didn't want to help them, and soon you'll regret! ;-)

Uh! And since everybody loves MacSlow... You rock dude! ;-)

[xwred1]

So I could try and use beryl with that new thing and blow more ram, switch to --indirect-rendering in compiz, or live with it til new drivers.

I was reading another thread here and people were talking about Aiglx. They were talking about turning on Option Aiglx in xorg.conf and/or passing --force-aiglx to beryl. Can someone explain that to me? That makes aiglx sound like something other than texture_from_pixmap to me.

[kmare]

Turning on the aiglx option with the nvidia drivers won't help you, as that option doesn't even exist in them. nvidia uses its own indirect rendering accelleration. tfp is just one more extention added to that accelleration path needed by opengl accelerated window managers like compiz, beryl, etc. It's only the DRI drivers who needs aiglx to accellerate indirect rendering.

[macemoneta]

Originally Posted by MacSlow

Not using GLX_EXT_texture_from_pixmap is not very wise. This avoids sharing the memory used by a windows pixmap between X11 and GL, thus doubling memory-usage. That's the main motivation for developing this extension in the first place, to avoid this waste of video-memory. The people behind beryl don't always think thoroughly (due to lack of experience with X11?) about the stuff they do. They tend to prefer quick&dirty solutions in order to gain some questionable merits (e.g. hacking input-transformation into beryl without the proper X11-extension done by Keith Packard).

What you say may be true, but I don't think it's significant. By using Beryl, I was able to enable many more desktop effects than Compiz allows, while using the 8776 driver. I need to use the older driver, because the 9xxx series won't work on my laptop. The GeForce 440Go I'm using only has 32MB of memory, so the wasted memory doesn't appear to be a significant issue.

The Fedora Extras team is in the process of adding the Beryl packages to the Fedora Extras repository. When they are done you will be able to use Beryl with a simple 'yum install beryl-gnome' (or beryl-kde, or just beryl for both).