Bug#790663: Extremely slow window dragging and very poor performance with KMS activated on RV100/M6 [Rage/Radeon Mobility Series]

Michel Dänzer michel at daenzer.net
Wed Jul 1 01:51:33 PDT 2015

On 01.07.2015 01:44, alfon wrote:
> Section "Extensions"
> 	Option		"Composite"		"Disable"
> EndSection

Why are you disabling this? If the desktop environment (DE) you're using
(which is it?) supports compositing, that might alleviate the problem.

> Section "ServerFlags"
> 	Option          "AIGLX"                 "off"
>         Option          "DRI2"			"off"
> EndSection

Disabling AIGLX isn't a good idea either. I don't think Option "DRI2"
has any effect.

> 	Option          "EXAVSync"              "on"
> 	Option 		"ColorTiling"		"off"
> 	Option 		"ColorTiling2D" 	"off"
> 	Option          "EXAPixmaps"            "on"

Does commenting out these options help?

> 	Option		"EnablePageFlip"	"off"

I recommend against disabling this.

> 		Virtual         2944 1080

This Virtual directive is unnecessary with KMS and causes the driver to
allocate at least twice as much VRAM as necessary for the front buffer.
Please try commenting it out.

> If I turn off hardware acceleration, the X environment is usable but still
> more slow than I used in UMS mode. In UMS mode (option radeon modeset=0)
> the Xorg window system directly crash

The Xorg radeon driver doesn't support UMS anymore.

Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer

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