Hi, Im a bit of a Linux newbie, just got up and running with Red Hat 8.0.

I've been a dual screen user in Windows for quite some time, using a 17 " @ 1280 x 1024 and a 14" @ 1024 x 768, running on a dual head 64 meg Radeon VE graphics card...

Prior to me setting up Xinerama so I can have my dual monitors in Linux, I had adequate video performance, which I checked by running tux racer - it was running in all its 3d glory with a decent framerate. However, now I've got my dual setup all running, performance has dropped drastically - If I run Tux Racer now, I only get like 1 or 2 fps, as if 3d acceleration isnt working now? Anyone got any experience with this before or a suggestion for a fix? Any help would be great, so thanks in advance.

Regards

Wilb.

*oops* double post.

Gah, triple post!

For some, maybe all, ATI video cards OpenGL does not work when you are using Xinerama. That is probably what you are experiencing.

Just thought I'd include my XF86Config in case it helps...

# File generated by anaconda.

Section "ServerLayout"
Identifier "Anaconda Configured"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" LeftOf "Screen0"
InputDevice "Mouse0" "CorePointer"
InputDevice "Mouse1" "SendCoreEvents"
InputDevice "Keyboard0" "CoreKeyboard"
Option "Xinerama" "on"
EndSection

Section "Files"
# The location of the RGB database. Note, this is the name of the
# file minus the extension (like ".txt" or ".db"). There is normally
# no need to change the default.
# Multiple FontPath entries are allowed (they are concatenated together)
# By default, Red Hat 6.0 and later now use a font server independent of
# the X server to render fonts.
RgbPath "/usr/X11R6/lib/X11/rgb"
FontPath "unix/:7100"
EndSection

Section "Module"
Load "dbe"
Load "extmod"
Load "fbdevhw"
Load "glx"
Load "record"
Load "freetype"
Load "type1"
Load "dri"
EndSection

Section "InputDevice"
# Option "AutoRepeat" "500 5"
# when using XQUEUE, comment out the above line, and uncomment the
# following line
# Option "Protocol" "Xqueue"
# Specify which keyboard LEDs can be user-controlled (eg, with xset(1))
# Option "Xleds" "1 2 3"
# To disable the XKEYBOARD extension, uncomment XkbDisable.
# Option "XkbDisable"
# To customise the XKB settings to suit your keyboard, modify the
# lines below (which are the defaults). For example, for a non-U.S.
# keyboard, you will probably want to use:
# Option "XkbModel" "pc102"
# If you have a US Microsoft Natural keyboard, you can use:
# Option "XkbModel" "microsoft"
#
# Then to change the language, change the Layout setting.
# For example, a german layout can be obtained with:
# Option "XkbLayout" "de"
# or:
# Option "XkbLayout" "de"
# Option "XkbVariant" "nodeadkeys"
#
# If you'd like to switch the positions of your capslock and
# control keys, use:
# Option "XkbOptions" "ctrl:swapcaps"
#Option "XkbOptions" ""
Identifier "Keyboard0"
Driver "keyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc101"
Option "XkbLayout" "gb" #Option "XkbVariant" ""
EndSection

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "PS/2"
Option "Device" "/dev/psaux"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "yes"
EndSection

Section "InputDevice"
Identifier "Mouse1"
Driver "mouse"
Option "Device" "/dev/input/mice"
Option "Protocol" "IMPS/2"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "C

And if OpenGL dont work with Xinerama enabled, that probably explains it then. Bit if a shame really - oh well

Cheers for the quick response!

Well can't you just take Xinerama off and run dualscreen anyway. Your mouse will be able to page over from screen to screen but you will not be able to drag windows over from screen to screen.
-NSKL

Hmm, using Dual Screen without Xinerama is confusing me... Just edited out the Xinerama comment in my XF86Config and restarted, and I get Gnome on my primary display, but my secondary display is just a black screen with an X pointer on it when I take my mouse accross... Is it possible to have 2 screens worth of Gnome in a similar vein to how Ive got it now using Xinerama / How I had it in XP without actually using Xinerama? I just assumed I needed Xinerama to have dual screens ya see... I can live with not being able to drag between screens - how would I actually go about getting windows from one screen to another without dragging though? A bit confused thats all, any help appreciated

To get GNOME on both screens without Xinerama you have to start it for the second screen (I hope you have a fast comp to run two GNOME sessions!) I dont remember the exact command for starting gnome on the second screen, check man startx
HTH
-NSKL

OK, I think thats helpful... Am at work at the minute so cant check it, but Im assuming Im having 2 seperate GNOME processes running, which I imagine will be resource hungry... Running an Athlon 1.1 Ghz with 256 meg so it should work OK, but it seems its not be the ideal solution... Suppose its either this or Xinerama though, and Ill have to decide whats best for me... Shame I cant just assign one of my 4 virtual desktops to the second screen, but hey ho...

Thanks,

Wilb

Yeah, xinerama disables DRI, which is what makes any flavor of OpenGL possible. Apparently there are a bunch of dual head freaks out there running xinerama under old 3.3.x based XFrees that don't have this problem. Its in the works to go away sometime, not soon.

Cheers,

Finegan

Where is screen0 and Screen1 defined here?

Shouldn't there be a:

Section "Screen"
Identifier "Screen0"
Device ATI Radeon
Monitor "Monitor0"
DefaultDepth 24
EndSection

Maybe you just didn't post it.

Bert

Ooops yeah, it seems the post got cut off half way through... Ive got my Screen definitions, Ill post my config again later when I get into RedHat...

Also search the forum because i know Acid_kewpie posted a copy of his XF86Config file together with commands on how to start the second screen without using xinerama, i'm sure he will be able to easily fix all your problems. As for me, i have dualhead with OpenGL working, but i use Nvidia's TwinView drivers, and they enable this..
So you might consider getting a nvidia dualhead card, ther are not very exopensive and work great.
HTH
-NSKL

Aye, Ive already had a search of the forum, and cried a few times after seeing peeps with NVidia and TwinView installed and running perfectly... Didnt really see anything about starting the 2nd screen without using Xinerama, but Ill have a search again.

Thanks muchly