Xfce Forum

sarunoatama

Member

Registered: 2008-10-28

Posts: 6

alt-tab cycling very slow with compositing on

Alt-tab cycling is very slow with XFWM with compositing on. Pressing alt-tab, it takes about a full second or more for the next application to focus and the icons to appear in the middle of the screen. I'm one who alt-tabs all day long and need it to be instantaneous.

Are there any tweaks or hidden settings that can help with this? Switching workspaces is also quite slow, but I can live with that.

My system:
AMD Turion64 ML-37(2.00GHz)
1GB DDR @ 400MHz
ATI Mobility Radeon X700 128MB
60GB 7200rpm
Gentoo x86-64
Kernel 2.6.25 gentoo r7
ATI proprietary binary drivers 8.542
XFCE/XFWM 4.4.2

I was previously using compiz-fusion and it was extremely fast after tweaking the delays down in both application cycling via alt-tab and workspace switching via alt-left/right-arrow. I don't really want to go back to compiz-fusion because it is overkill for what I want. XFWM is almost perfect.

Thanks!

mali2297

Member

From: Sweden

Registered: 2008-07-30

Posts: 14

Re: alt-tab cycling very slow with compositing on

I have the same graphics card and experienced the same problem, although I use the open source driver.

I solved it by editing the file /etc/X11/xorg.conf. Here's my present copy:

# /etc/X11/xorg.conf (xorg X Window System server configuration file)
#

Section "Files"
        FontPath     "/usr/lib/X11/fonts/misc:unscaled"
        FontPath     "/usr/lib/X11/fonts/Type1"
        FontPath     "/usr/lib/X11/fonts/TTF"
        FontPath     "/usr/lib/X11/fonts/75dpi:unscaled"
        FontPath     "/usr/lib/X11/fonts/100dpi:unscaled"
    FontPath     "/usr/lib/X11/fonts/msttcorefonts"
        FontPath     "/usr/lib/X11/fonts/Speedo"
        FontPath     "/usr/lib/X11/fonts/cyrillic"
EndSection

Section "Module"
       # old bitmap font support (no longer needed as of xorg7.x)
       Load    "bitmap"
       # a collection of X protocol extensions that you want but shouldn't even be loadable
       Load    "extmod"
       # freetype fonts
       Load    "freetype"
    # type 1 fonts (obsolete)
       # Load    "type1"
       # layer below vbe that emus x86 real mode so you can call into vbios
       # vesa bios interface for card setup stuff
       Load    "int10"
       Load    "vbe"
       # serial bus over which you speak the ddc protocol to get info from the monitor (already built-in)
       Load    "i2c"
       # Load    "ddc"
       # direct rendering infrastructure which makes opengl go fast (disabled)
       Load    "dri"
       # glx and glcore implement opengl
       Load    "glx"
       Load    "GLcore"
       # double buffering extension (no apps use?)
       Load    "dbe"
       # 1 of 3 extensions for application automation (obselete)
       # Load    "record"
    # Available?
    # Load    "v4l"
EndSection

Section "InputDevice"
    Identifier    "Generic Keyboard"
    Driver        "kbd"
    Option        "CoreKeyboard"
    Option        "XkbRules"    "xorg"
    Option        "XkbModel"    "pc105"
    Option        "XkbLayout"    "se"
EndSection

Section "InputDevice"
    Identifier    "Configured Mouse"
    Driver        "mouse"
    Option        "CorePointer"
    Option        "Device"        "/dev/input/mice"
    Option        "Protocol"        "ImPS/2"
    Option        "ZAxisMapping"        "4 5"
    Option        "Emulate3Buttons"    "true"
EndSection

Section "InputDevice"
    Identifier    "Synaptics Touchpad"
    Driver        "synaptics"
    Option        "SendCoreEvents"    "true"
    Option        "Device"        "/dev/psaux"
    Option        "Protocol"        "auto-dev"
    Option        "HorizScrollDelta"    "0"
    Option         "SHMConfig"         "on"
EndSection

Section "Device"
    Identifier    "ATI Radeon Mobility X700"
    Driver        "radeon"
    BusID        "PCI:1:0:0"
    Option         "monitor-LVDS"         "Acer inbyggd"
    # amount of video RAM to reserve for OpenGL textures
    # Option         "FBTexPercent"        "50"
    # enable  DRI support
    Option      "DRI"           "true"
    # 3D applications benefits from tiled mode 
     Option          "ColorTiling"        "true"
    # disable DDC to fix huge fonts
    Option         "DDC"             "false"
    # set AGP data transfer rate (used only when DRI is enabled)
    Option          "AGPMode"            "4"     
    # either XAA or EXA (XAA is the default and safe choice)
    Option          "AccelMethod"        "EXA"   
    # only works with accelmethod "XAA"
    Option          "EnablePageFlip"     "true" 
    # accelerated EXA DownloadFromScreen hook
     Option          "AccelDFS"           "true"  
    # for laptop users, it saves energy when in battery mode.
    Option          "DynamicClocks"      "on"    
    # speed up movie playback (can in rare cases cause instability)
    Option          "DMAForXv"           "true"  
    # size of the "GART" that xorg will use
    Option          "GARTSize"           "16"
    # hardware render acceleration
    Option          "RenderAccel"       "true"
    Option          "backingstore"      "off"
EndSection

Section "Monitor"
    Identifier    "Acer inbyggd"
    Option        "DPMS" "true"
    HorizSync    28-50
    VertRefresh    43-75
    DisplaySize     332 212
EndSection

Section "Screen"
    Identifier    "Default Screen"
    Device        "ATI Radeon Mobility X700"
    Monitor        "Acer inbyggd"
    DefaultDepth    24
    SubSection "Display"
        Depth        16
        Modes        "1280x800" "800x600"
    EndSubSection
    SubSection "Display"
        Depth        24
        Modes        "1280x800" "800x600"
    EndSubSection
EndSection

Section "ServerLayout"
    Identifier    "Default Layout"
    Screen        "Default Screen"
    InputDevice    "Generic Keyboard"
    InputDevice    "Configured Mouse"
    InputDevice    "Synaptics Touchpad"
    Option          "AIGLX"         "true"
EndSection

Section "DRI"
       Group     0
    Mode    0666
EndSection

Section "Extensions"
           Option  "Composite"   "Enable"
    Option  "RENDER"     "Enable"
        Option  "DAMAGE"     "Enable"
EndSection

Section "ServerFlags"
    Option        "blank time" "0"
    Option        "standby time" "0"
    Option        "suspend time" "0"
    Option        "off time" "10"
EndSection

I think it was the options in "Extensions" that solved the problem.

sarunoatama

Member

Registered: 2008-10-28

Posts: 6

Re: alt-tab cycling very slow with compositing on

Thanks for replying. I tried the open source radeon driver which didn't have the lag with alt-tab cycling, but it had little anomalies all over the place and the whole fake xinerama thing was very annoying since I use a "big desktop" setup. Also, I could not get opengl to work at all despite tweaking every config variable and completely removing the proprietary ATI driver and reinstalling/reconfiguring mesa, xorg, and the drivers.

The proprietary ATI/AMD drivers almost work perfect for what I need except for the alt-tab cycling in XFWM with compositing on. If anyone has any other ideas to get that working better, I'd really appreciate them.

sarunoatama

Member

Registered: 2008-10-28

Posts: 6

Re: alt-tab cycling very slow with compositing on

Forgot to mention above the other components of my system:
xorg server 1.4.2
xorg x11 7.3
mesa 7.2

sarunoatama

Member

Registered: 2008-10-28

Posts: 6

Re: alt-tab cycling very slow with compositing on

If anyone finds this thread, this issue boils down to the AMD/ATI drivers not having X RENDER acceleration working yet (as of driver 8.10 aka build 8.542). I'll post again if AMD/ATI ever fixes it or if I find out how to get the open source drivers to do what I want (XAA, DRI, and big desktop w/ real xinerama).

See this thread http://phoronix.com/forums/showthread.php?t=13676 and file a comment in the linked bugzilla bug http://ati.cchtml.com/show_bug.cgi?id=1338 if this affects you.