Woah! What's this?

[glennzo]

Help! Guys, I just installed Ubuntu 8.04 as a secondary OS. The display is odd to say the least. Check the screen shot. This is with an ATI Radeon 9550 using the FGLRX driver for xorg. Any idea what causes this?

[JohnVV]

besides the driver , no idea

[glennzo]

I tried Driver "ati" and Driver "radeon". What's in the screen shot didn't happen with either of those drivers but the screen redraw was extremely slow.

[glennzo]

It's an incompatibility between the fglrx and "visual effects" which is turned on by default in 8.04. I turned off visual effects and that weirdness is gone.

[notageek]

It's an incompatibility between the fglrx and "visual effects"

Why would that happen? As far as I know, fglrx "works" with "visual effects". BTW I do not have any practical experience with this, I'm just stating what I read off Leigh's signature.


PS: Did you just ask a Ubuntu question in Fedora forums? ;)

[glennzo]

Why would that happen? As far as I know, fglrx "works" with "visual effects". BTW I do not have any practical experience with this, I'm just stating what I read off Leigh's signature.Yes, but isn't there a difference between visual effects and compiz? I believe that visual effects is the same as Fedora's desktop effects. I get the same results when I run Fedora on that box.PS: Did you just ask a Ubuntu question in Fedora forums? ;)Yes I did. I know that I can get knowledgeable answers here. Not always so friendly over at the Ubuntu forums.

[notageek]

Well, I thought visual effects is same as desktop effects, which is same as compiz.

I get the same results when I run Fedora on that box.

Do you mean you get the same distorted screen in Fedora too?

Yes I did. I know that I can get knowledgeable answers here. Not always so friendly over at the Ubuntu forums.

No comments :D

[glennzo]

Yes sir, I get the same distortion when I run Fedora on that computer.

[notageek]

Here are the links from Leigh's sig, (maybe you've already tried this)

http://forums.fedoraforum.org/showthread.php?t=155503&page=1&pp=10
http://fedoraguide.info/index.php/Fedora8#ATI

But beyond that prolly you need an expert help.

[notageek]

Well what I meant was, I don't know whats going wrong besides the driver.

Sorry to have mindlessly wandered onto your thread. :D

[Hlingler]

Help! Guys, I just installed Ubuntu 8.04 as a secondary OS. The display is odd to say the least. Check the screen shot. This is with an ATI Radeon 9550 using the FGLRX driver for xorg. Any idea what causes this?This looks/sounds like maybe the "tearing" effect that I've read about WRT C-F: as I understand it, the graphics hardware can fill up the framebuffer faster than the display can re-draw the screen, so you get this "tearing" effect where the two (or more) frames over-lap. Off-hand, I can't recall or find where I read this - somewhere on the C-F site maybe? IIRC a possible solution is to enable "sync to VBlank" to synchronize/limit the graphics card output to the display draw/refresh rate.

Or, maybe I'm completely mis-guided.....

V

[glennzo]

I've been through those threads several times in the past. Haven't looked at them yet for this install but I'm sure I'll be reading them again very soon. Never mind about mindlessly wandering into my thread. Any help is appreciated. While I'm not necessarily trying to get Compiz working on the box it would be nice just to get 'normal' graphics acceleration going. The display, after a basic Fedora install, is terribly sluggish. Just not responsive at all. I've fiddled with this before to no avail so I've installed Ubuntu and PCLinuxOS to see if there's any difference. Not really. Now I'm installing Debian but I suspect that instead of installing several distros for comparison my time could be better spent learning a little more about the ATI drivers as they relate to specific cards under Fedora.

[glennzo]

This looks/sounds like maybe the "tearing" effect that I've read about WRT C-F: as I understand it, the graphics hardware can fill up the framebuffer faster than the display can re-draw the screen, so you get this "tearing" effect where the two (or more) frames over-lap. Off-hand, I can't recall or find where I read this - somewhere on the C-F site maybe? IIRC a possible solution is to enable "sync to VBlank" to synchronize/limit the graphics card output to the display draw/refresh rate.

Or, maybe I'm completely mis-guided.....

VSomething for me to look into. What is WRT and C-F?

Ah, C-F = Compiz-Fusion.

[Hlingler]

"WRT"=with respect to
"C-F"=Compiz-Fusion

This "tearing" phenomenon does not necessarily apply only to C-F, but any compositing effects.

V

EDIT: Here it is, from http://wiki.compiz-fusion.org/GeneralOptions:Display Settings
[...]
Sync To VBlank
When this option is enabled, Compiz will only update the screen in sync with the screen's refresh rate. This can reduce tearing artefacts, but may also cause animations to feel stiffer.And from http://wiki.compiz-fusion.org/FAQ:The desktop is slow and unresponsive overall

You will need to launch Compiz with --loose-binding. This may break VSync and cause tearing.

[glennzo]

I'm not using Compiz on the Ubuntu system. Just good old Metacity, so I'm interested in getting the best video acceleration / screen refresh I can get with this card and that WM as the video performance is dreadful. When I disabled 'visual effects' this issue disappeared.

[A.Serbinski]

As I understand it, the 9550 is supported by the open source drivers, including AIGLX and Compiz. Therefore you should NOT use the proprietary drivers as they have nothing to add, and are, in fact, quite broken with that hardware. There's not much incentive for AMD to update the proprietary drivers given that they are moving towards open source drivers and that that hardware is supported by open source drivers.

https://help.ubuntu.com/community/RadeonDriver