Gentoo ATI Radeon FAQ

Last updated: 16/05/07



This document is intended to help users of Gentoo Linux install and use the binary Linux drivers provided by ATI. If you have anything you want to add, email me: wedge__ AT fastmail.fm or PM me on the Gentoo forums (my username is Wedge_)

Section 1 - Information about the drivers

1.1 - Why use the ATI binary drivers?
1.2 - Where can I get the drivers?
1.3 - Which cards are supported by the driver?
1.4 - Are PCI / PCIe cards supported?
1.5 - Which version should I use?
1.6 - Can I use the "radeon" driver or not?
1.7 - Where can I get diagnostic information if I have a problem?
1.8 - What can I use to benchmark performance?
1.9 - Can I overclock my Radeon card under Linux?
1.10 - Can I use the drivers with Xorg?
1.11 - Where can I get more information about the drivers?

Section 2 - Kernel configuration

2.1 - Which kernel options are important for the ATI drivers?
2.2 - Which kernel versions can I use with the drivers?
2.3 - Do I need to select the "ATI chipset support" kernel option if I have an ATI card?

Section 3 - Installing the drivers

3.1 - How do I install the drivers?
3.2 - What is aticonfig?
3.3 - Can I still use the fglrxconfig tool to configure the driver?

Section 4 - Troubleshooting

4.1 - I get frequent lockups on games like Tux Racer, Return to Castle Wolfenstein, or Enemy Territory, what can I do to fix it?
4.2 - When I try to start X, it fails with a message saying it was 'unable to acquire AGP, error "xf86_ENODEV"'
4.3 - When I try to start X, it fails with a message saying it was 'unable to acquire AGP, error "xf86_ENOMEM"'
4.4 - I tried to emerge the drivers, but it didn't work. The error message was "cannot find -lGL"
4.5 - X is ignoring my modeline setting, or I can't get the refresh rate I want
4.6 - When I try to run the fgl_glxgears program, I get an error saying "couldn't get fbconfig"
4.7 - When I try to run "modprobe fglrx" it doesn't work
4.8 - X appears to start correctly, but everything seems slow and I don't have 3D acceleration
4.9 - I'm having problems with a VIA KT400/KT400A motherboard and a 2.4 kernel
4.10 - I'm trying to use the driver with "UseInternalAGPGART" set to "yes", but it doesn't work
4.11 - My glxgears score is very low (<120), but everything seems to be working. Why?
4.12 - I have a Radeon 9800XT, and direct rendering doesn't work. How can I fix it?
4.13 - I have an Epox 8RDA motherboard and can't get direct rendering to work using a 2.6 kernel
4.14 - I get errors about MTRR overlaps in my logs, how can I get rid of them?
4.15 - What does this "(WW) fglrx: No matching Device section for instance (BusID PCI:x:0:1) found" message mean?
4.16 - I'm using the Xorg Xserver and 3D acceleration isn't working
4.17 - Why does my system hang when I close down X?
4.18 - I get error messages from fglrx in my dmesg output, how can I get rid of them?
4.19 - Do the ATI drivers support 16 bit colour depth?
4.20 - I have an AMD64 system - can I use the drivers?
4.21 - X fails to start and the error message mentions "gnu_dev_makedev"
4.22 - Emerging the drivers fails at "probing for VMA API version... "
4.23 - OpenGL applications fail with the error "libGL error: InitDriver failed"
4.24 - My X server fails to start - the error is "Caught signal 11"
4.25 - X fails to start with an X300 card
4.26 - Celestia segfaults when I try to run it
4.27 - How do I enable or disable vertical sync?
4.28 - Can my CFLAGS prevent the driver from working?
4.29 - Can my USE flags cause problems?
4.30 - Why are all 3D applications only displaying a black screen?
4.31 - Why doesn't the RANDR extension work?
4.32 (AMD64) - X starts up with a corrupted screen and then locks up
4.33 - I'm using a hardened version of GCC and can't get direct rendering to work
4.34 - 3D applications fail to start and/or display lots of errors about "FGLTexMgr"
4.35 - 3D acceleration doesn't work after enabling the new Composite extension in Xorg
4.36 - Games like Tuxracer and Chromium fail to start, but 3D acceleration is enabled
4.37 - Why don't I have XVideo support?
4.38 - Is there any way to fix the memory leaks in Neverwinter Nights?
4.39 - How do I get TV-out working on a Notebook with ATI Radeon Mobility Chipset?
4.40 - X appears to be starting up, but I can only see a black screen
4.41 - My card isn't detected by the driver, is there anything I can do?
4.42 - I've emerged ati-drivers but I don't have an fglrx module, why?
4.43 - X is crashing when I try to drag windows or run applications, why?
4.44 - I get "out of vmalloc space" errors in my dmesg output
4.45 - I have a 64-bit system and can't get 3D acceleration in 32-bit applications
4.46 - How can I enable suspend/resume with direct rendering enabled?
4.47 - I'm getting errors loading the GLX module after replacing an nvidia card with an ATI card
4.48 - Why can't I get direct rendering enabled with AGP and PCI cards installed?
4.49 - Why can't I get the "new-login" feature of xscreensaver to work without crashing?
4.50 - None of this stuff helped! Is there anything else I can do?

Section 5 - Miscellaneous

Section 6 - Credits

Section 1 - Information about the drivers

Question 1.1: Why use the ATI binary drivers?
The ATI binary drivers are at present the only drivers which support 3D acceleration on cards based on the R3xx and R4xx chipsets. This includes recent cards such as the 9500, 9600, 9700, and 9800 series, plus the high end mobility chipsets and X-series cards.

An effort to develop an opensource driver for the high end Radeon chipsets is underway here. If you want to try this driver, be aware that it is still under development and that you may encounter serious problems.

Question 1.2: Where can I get the drivers?
All recent driver versions can be found in the portage tree, under the category x11-drivers/ati-drivers. Note that the most recent version(s) may be marked as unstable (~x86). To emerge these versions, assuming that you're not already running an ~x86 system, you should do the following: 
   mkdir -p /etc/portage
   echo "x11-drivers/ati-drivers ~x86" >> /etc/portage/package.keywords
You should then be able to emerge all versions of the driver, unless they are hardmasked for some reason.

The drivers can also be downloaded directly from the ATI website in the same way as for Windows drivers. Go to http://www.ati.com/support/driver.html, and select "Linux" from the first column. Then pick "Graphic Driver" from the second column. Pick the correct type of card from the last column and click the "Go" button to be taken to the download page.

Question 1.3: Which cards are supported by the driver?
The following list of supported cards is taken from the release notes of the 8.30.3 driver version (http://www2.ati.com/drivers/linux/linux_8.30.3.html). PCIe support is available in all driver versions since 3.14.1. Note that this list is not always up to date - check the release notes for the latest drivers for the most current information. NOTE: Older ATI cards should be supported by the opensource "radeon" and "ati" drivers that are supplied as part of XFree or Xorg. Also note that if you use an older version of the driver, it may not support all the cards listed above. If you have a newer card that is not listed here, it may be possible to get the driver working with it using the techniques described in Q4.41.

Question 1.4: Are PCI / PCIe cards supported?
PCIe cards are supported in all recent driver versions as mentioned in Q1.3. PCI cards are apparently supported as well (eg R9200 PCI) but several people have had great difficulty in attempting to get the driver working with such cards. A possible alternative if you're in this situation is to use the opensource "radeon" driver instead.

Question 1.5: Which version should I use?
It is usually best to use the most recent version of the driver (currently 8.36.5). Older versions are available in portage if you have problems with the newest release. To emerge an older version, use the following style of emerge command: emerge =ati-drivers-3.2.8-r1. This tells portage to install that specific version of the package rather than the latest available version.

Sometimes, the latest driver version will not be available if you're running a "stable" system (ie ACCEPT_KEYWORDS="x86" instead of "~x86", "amd64" instead of "~amd64"). If you are in this position and want to install the latest driver (this can be necessary if you have a new card not supported by the older drivers), you should use the /etc/portage/package.keywords file to selectively unmask the relevant packages (eselect, eselect-opengl, ati-drivers, ati-drivers-extra). For example, to install ati-drivers and ati-drivers-extra on an x86 system, you would add these two lines to /etc/portage/package.keywords (create the directory and file if they don't exist already):
   x11-drivers/ati-drivers ~x86
   x11-drivers/ati-drivers-extra ~x86
Question 1.6: Can I use the "radeon" driver or not?

The "radeon" driver has support for all recent Radeon cards, but does not support 3D acceleration for newer cards (generally those based on the R300/R350 chipset and later, like the 9600 and 9800). For other cards, like the R8500, R9000, or R9200, it should support full 3D acceleration, so you can use it as an alternative to the ATI driver. As mentioned in Q1.3, it also supports many older cards that the ATI binary driver does not. For more information, see the manpage for the driver (man radeon).

Question 1.7: Where can I get diagnostic information if I have a problem?

Question 1.8: What can I use to benchmark performance?
Your best bet is probably to run some timedemos in a game such as Unreal Tournament 2004 or Quake 3 (both of these have free demos you can use). However, do not try to use the well known glxgears application for accurate performance measurements. It is not intended to be a benchmark.

Question 1.9: Can I overclock my Radeon card under Linux?
Yes. Gentoo user Hasw has written a Radeon overclocking tool - see this forum thread.

Question 1.10: Can I use the drivers with Xorg?
Yes, the drivers have had Xorg support for some time now.

Question 1.11: Where can I get more information about the drivers?
As the ATI driver isn't provided with much in the way of documentation, a project has been started to produce a complete set of man pages for the driver and it's associated applications (eg aticonfig, fgl_glxgears). The project is hosted at http://cvs.wgdd.de/cgi-bin/cvsweb/fglrx_man/. Although it's intended for Debian distros, the information it contains will apply equally well to other distros, such as Gentoo, and they are currently looking for contributions, particularly for the "fglrx" manpage.

Section 2 - Kernel configuration

Question 2.1: Which kernel options are important for the ATI drivers?
The following kernel options must be set correctly: NOTE 1: in 2.4 kernels, the "Device drivers" category that the last 3 settings are normally found under does not exist. Instead, you should find them in the "Character devices" section straight from the top level menu.
NOTE 2: if you have a PCIe card, the AGP settings should be irrelevant. If you encounter problems, make sure you're using a recent kernel and the latest driver version. Some people have also reported that they had to enable AGP for their PCIe cards to work.

AMD64 users: if you're running a 32-bit kernel, follow the advice above. If you're using an AGP card, you should also select the Device drivers -> Character Devices -> AMD Opteron/Athlon64 on-CPU GART support option. If you compile it as a module, it will be called "amd64-agp" and should be loaded before the fglrx module, along with the other kernel AGP modules (see Q3.1). If you're using a PCIe card, then as noted above, it shouldn't be necessary to enable AGP, but it may be worth trying if you have problems.

If you're running a 64-bit kernel, then the /dev/agpgart support and AMD Opteron/Athlon64 on-CPU GART support will usually be enabled automatically. Again, if you don't have an AGP card, it should be safe to disable these options.

Question 2.2: Which kernel versions can I use with the drivers?
All versions of the drivers in the portage tree should be compatible with 2.4.x kernels. Any version from 2.9.13-r1 or above should also work on 2.6 kernels. However, there is no guarantee that the driver will compile against heavily patched kernels. It is impossible for ATI to test the drivers against any more than the most common kernel versions. If you like to run the latest nitro/mm/love/ck/cko-sources or any of the other custom patchsets out there, be aware that they may well break the driver in some way. This can show up either as a failed compilation of the driver, or as a failure to load the fglrx kernel module. In many cases patches to fix such problems can be found on the Gentoo or Rage3D forums, but you can't always rely on this. If you aren't able to fix the problem yourself, and can't find a patch, you should revert to a previous kernel version.

Question 2.3: Do I need to select the "ATI chipset support" kernel option if I have an ATI card?
No, you do not usually have to enable this option. If you read the attached help text, you will see:
"This option gives you AGP support for the GLX component of XFree86 4.x on the ATI Radeon IGP family of chipsets".
In other words, you don't need this unless you have a system with an IGP integrated graphics chipset. If you have a normal AGP card, ignore this option.

Section 3 - Installing the drivers

Question 3.1: How do I install the drivers?
NOTE: this is based on the guides that were originally posted in the following thread on the Gentoo forums: http://forums.gentoo.org/viewtopic.php?t=73260.
  1. The first stage of installing the drivers is configuring your kernel properly. Q2.1 lists the relevant options and what they should be set to.
  2. Next, check that the /usr/src/linux symlink is pointing to the directory containing the sources for your current kernel. If you're not sure which kernel version you're running, use the uname -r command to display it. As an example, if you're running kernel 2.6.1, then ls -l /usr/src/linux should show the following:
    lrwxrwxrwx 1 root root 26 Feb 6 14:19 /usr/src/linux -> /usr/src/linux-2.6.1. If the symlink is correct, move on to step 3. If it's not correct, run the command rm -f /usr/src/linux followed by ln -s /usr/src/linux-`uname -r` /usr/src/linux, which will recreate the symlink and point it to the correct kernel source directory.
  3. If you had to change any kernel options in step 1, you should now recompile the kernel and reboot. To recompile the kernel run the following commands from the /usr/src/linux directory.
    For 2.4 kernels: make dep && make clean bzImage modules modules_install
    For 2.6 kernels: make && make modules_install

    If you have to mount your /boot partition, do so now (mount /boot), then copy your new bzImage over: cp /usr/src/linux/arch/i386/boot/bzImage /boot/<your kernel name>
    Remember to update your bootloaders configuration file if necessary, then reboot.
  4. Now you should be ready to install the drivers, which you can do by running emerge ati-drivers. Pay attention to the output displayed by the ebuild - it will NOT abort if the fglrx kernel module fails to compile, and this is easy to miss. If you find that you get a "Module fglrx not found" error when trying to load the fglrx module at a later stage, this is often the cause.
  5. When the emerge has completed, you should now configure your /etc/X11/xorg.conf file. If you're just upgrading from a previous driver version, it will usually be OK to continue using your existing configuration file. However, there may be occasions when a new driver introduces new settings that have to be configured in the /etc/X11/xorg.conf file.

    Configuring the /etc/X11/xorg.conf file was originally done using the fglrxconfig application (see Q3.3), but ATI now recommend using aticonfig, which was introduced in recent driver versions. aticonfig is designed to update your existing configuration rather than replace it with a new one, which is a bit more convenient. A basic configuration can be produced simply by running the command aticonfig --initial --input=/etc/X11/xorg.conf. Run the application without arguments for a listing of the various parameters and some examples. You can run aticonfig again in future to enable/disable any of the other various settings the driver supports.

    If you find that you get a "command not found" error when trying to run aticonfig, you may have to run env-update && source /etc/profile before it will work. This happens because aticonfig is installed into /opt/ati/bin, and this location won't normally be part of your $PATH environment variable ($PATH contains the directories where the shell looks for executables)

  6. Run opengl-update ati to switch to the ATI OpenGL libraries. opengl-update is being deprecated in favour of eselect. You should already be able to use the replacement command eselect opengl set ati if your system is up to date.
  7. If you're using the kernel AGP support (see step 4), and have it compiled as modules, load them now. For 2.4 kernels, you just need to load the agpgart module. For 2.6 kernels, you need to load agpgart and a second module, the name of which is dependent on your motherboard. nForce users should load nvidia_agp, VIA users via_agp, Intel users intel_agp, and so on. You should add the modules that you require to /etc/modules.autoload.d/kernel-2.4 or /etc/modules.autoload.d/kernel-2.6 to ensure they are loaded on every boot. You should also add the fglrx module to the list, after the kernel AGP modules.
  8. Before starting X, ensure that you have all the necessary modules loaded and that your xorg.conf file is configured to your liking.
  9. Once X is started, you can check if Direct Rendering (ie 3D acceleration) is working by running glxinfo | grep direct. This should display direct rendering: Yes if everything is working.
  10. Finally, remember that you need to emerge the ati-drivers ebuild each time you change your kernel version. Remember to update the symlink as described above before doing so.
Question 3.2: What is aticonfig?
aticonfig is the name of a new application included with recent versions of the ATI Linux driver. Unlike the fglrxconfig application, which generates an entirely new xorg.conf file, aticonfig can be used to make changes to an existing xorg.conf. For example, you can use the aticonfig --initial command to insert a "Device" section for your ATI card into an xorg.conf. Run the application without arguments for a complete listing of options and some usage examples. aticonfig is intended to replace fglrxconfig at some point in the future as a means of configuring the driver.

Question 3.3: Can I still use the fglrxconfig tool to configure the driver?
For the moment, yes, but it may be removed in the future (although it will still obviously be included in older drivers). To install the driver using fglrxconfig, follow the procedure in Q3.1 up to step 5. Instead of running aticonfig, run fglrxconfig and answer the questions it asks. Remember that unlike aticonfig, fglrxconfig will replace your existing configuration file by default. Be aware that it may not set up your mouse or keyboard correctly - if you have a working configuration file, keep a copy of it somewhere so that you can refer to it if you encounter problems. If you find that you get a "command not found" error when trying to run fglrxconfig, you may have to run env-update && source /etc/profile before it will work. This happens because fglrxconfig is installed into /opt/ati/bin, and this location won't normally be part of your $PATH environment variable ($PATH contains the directories where the shell looks for executables)

At one point, the program will ask you "Do you want to use the external AGP GART module (y/n)? [n]". It wants to know if it should rely on the AGP support contained in the driver itself, or if it should use the kernels own AGP modules. The answer to this question will vary from system to system - sometimes either option will work, sometimes only one will work. Answering "n" means use the drivers AGP support, "y" means use the kernel AGP support.

This setting can be changed later on through the "UseInternalAGPGART" option in your X configuration file (/etc/X11/xorg.conf or /etc/X11/XF86Config-4). Setting "UseInternalAGPGART" to yes means "use the AGP support in the driver", and setting it to no means "use the AGP support from the kernel" (this requires kernel AGP to be enabled - see Q2.1).

There is some potential for confusion here because of the way fglrxconfig asks its question, so I'll try and state things explicitly. When you answer "yes" to the question ("Yes, I want to use the kernel AGP support"), it will set "UseInternalAGPGART" to "no". When you answer "no" ("No, I want to use the AGP support in the driver"), it will set "UseInternalAGPGART" to "yes". Make sure you don't get mixed up between the answer to the question and the value of the "UseInternalAGPGART" setting.

Note: fglrxconfig versions in the latest drivers (>= 8.10.19) should produce an xorg.conf by default. Older versions may produce an XF86Config-4 instead, so Xorg users should rename the config file to /etc/X11/xorg.conf before continuing. Even more important, Xorg 6.8 users should edit the new config file and change the keyboard driver name from "Keyboard" to "kbd". If you don't do this, X will fail to start. The reason for this is that the driver name changed between Xorg 6.7 and 6.8, and older versions of fglrxconfig may still use this naming. The most recent versions no longer have this problem.

Section 4 - Troubleshooting

Question 4.1: I get frequent lockups on games like Tux Racer, Return to Castle Wolfenstein, or Enemy Territory, what can I do to fix it?
Try upgrading to the latest version of the drivers. For games based on the Quake 3 engine (Q3A, RTCW, ET etc), try running them in the following way: et +set r_ext_compiled_vertex_array 0. You can also disable the "r_ext_compiled_vertex_array" setting permanently by setting it to 0 in the game console or your config file. However, disabling this setting may decrease performance.

This problem should not exist in the recent versions of the driver (>3.2.8).

Question 4.2: When I try to start X, it fails with a message saying it was 'unable to acquire AGP, error "xf86_ENODEV"'
This error can have many causes, but some of the most common are: Question 4.3: When I try to start X, it fails with a message saying it was 'unable to acquire AGP, error "xf86_ENOMEM"'
This error is generally more difficult to diagnose and fix than the "xf86_ENODEV" error. Some things to try: Question 4.4: I tried to emerge the drivers, but it didn't work. The error message was "cannot find -lGL"
(this problem should be fixed)
As root, do this: 
   opengl-update xfree / opengl-update xorg-x11
   emerge ati-drivers
   opengl-update ati

Question 4.5: X is ignoring my modeline setting, or I can't get the refresh rate I want
Try changing the "IgnoreEDID" setting in /etc/X11/xorg.conf to "on".

NOTE: This option now appears to be ignored by newer driver versions. In addition, many people have reported problems getting custom modelines to work with driver versions later than 8.14.13 - see this bug report. Downgrading to 8.14.13 seems to be the best solution for the moment.

Question 4.6: When I try to run the fgl_glxgears program, I get an error saying "couldn't get fbconfig"
Make sure you have run eselect opengl set ati (or opengl-update ati) as root.

Question 4.7: When I try to run "modprobe fglrx" it doesn't work
There are a number of possible causes for this. The first thing to do is to get the error message given when you try to load the module. If the output from modprobe doesn't tell you anything, check the last few lines of "dmesg" output just after you've run it. There will usually be a better description of the error there.

Check that your /usr/src/linux symlink is pointing to the set of kernel sources that you are currently using. If the link isn't correct, the module will be generated for the wrong kernel and modprobe won't be able to find it. To update the link, use the following command: ln -sf /usr/src/linux-2.x.y /usr/src/linux

If modprobe cannot find the module even after checking the /usr/src/linux symlink is correct, the problem is usually that the compilation of the module has failed. The ati-drivers ebuilds will complete successfully even if the module fails to compile, so it is easy to miss this problem. Re-run the emerge, and watch carefully for errors in the compilation process, particularly if you are using a heavily patched kernel (see Q2.2).

If modprobe fails with an "Invalid module format message", and the dmesg output contains lines similar to this: "fglrx: version magic '2.6.1-gentoo-r1 SMP preempt K7 gcc-3.3' should be '2.6.1-gentoo-r1 SMP preempt K7 gcc-3.2'" then it usually means that you have compiled the drivers with a different gcc version than you compiled the kernel with. To fix this, just recompile the drivers with the same gcc version as the kernel (the second one in the message above), or recompile both driver and kernel with the same version. This error may also be caused in other ways. For example, if you have compiled a kernel with 4k stacks support, but are still using the fglrx module from a normal 8k stacks kernel, you will get a message similar to that above, except that the difference between the two versions will be that one mentions "4KSTACKS" while the other does not. In this case, the solution is to remerge the drivers and load the newly compiled module.

If the "dmesg" output mentions "unresolved symbols", it's possible that the kernel version you're using has had some patches applied to it that aren't compatible with the drivers (Q2.2). The easiest thing to do is try a different kernel version. If you can create a patch for the drivers that fixes the problem, submit it to bugs.gentoo.org so that it can be included in future releases of the ebuild.

If the "dmesg" output says something similar to "the fglrx module must be loaded before any other DRM module", then it probably means that you still have DRM support in your kernel, which has been loaded before the fglrx module and is preventing it from working properly. Another indication of this problem is an "Operation not permitted" error from modprobe. See Q2.1 for more information on the DRM settings in the kernel.

If the error is "No device found", it means the driver does not support your card. If you have an older card, there's not much you can do except try the opensource "radeon" driver. If you have a new card, it's possible that the driver simply hasn't been updated with the necessary information to allow it to recognise your device. It can be made to work with a little extra effort. See Q4.41 and fglrx_binary_edit.

Question 4.8: X appears to start correctly, but everything seems slow and I don't have 3D acceleration
You may have forgotten to load the "fglrx" module. The module is necessary for 3D acceleration to work, but is not always loaded automatically by X. It's best to add it to your /etc/modules.autoload.d/kernel-2.x file, where x is the correct kernel version. This ensures it's loaded before you start X. The fglrx entry should be placed after the kernel AGP modules, if you are using them.

If the fglrx module is loaded (ie it appears in the output of the lsmod command), then something else must be wrong. Check your X logfile (/var/log/XFree86.0.log or /var/log/Xorg.0.log) for errors. If you find an error message that looks like this:
   (EE) fglrx(0): incompatible kernel module detected - HW accelerated OpenGL will not work
it means that the version of the fglrx module you have loaded does not match the version of the driver you have installed. This can happen if you change driver version without unloading and reloading the fglrx module (or rebooting). To fix this error, you can simply reboot, or run rmmod fglrx && modprobe fglrx which will unload the old module and load the new one.

If you have an nForce2 board, try toggling the "Primary VGA Bios" setting (in the BIOS obviously :)) to the opposite of whatever it currently is. This seems to be quite rare (only 1 case I know of) but it did seem to enable 3D acceleration where it wasn't working before.

It may also help in some situations to emerge libstdc++-v3, which is a "compatibility package for running binaries linked against a pre gcc 3.4 libstdc++". If your Xorg log shows that things appear to be starting up OK, but you don't have direct rendering enabled, this may be the problem. See here and here for more information.

Question 4.9: I'm having problems with a VIA KT400/KT400A motherboard and a 2.4 kernel
Many people have had problems with these motherboards in combination with 2.4 kernels, mainly because of AGP issues. The AGP support in 2.4 kernels currently doesn't support the KT400 chipset properly, and you may get messages during bootup along the lines of "agpgart: unable to determine aperture size". The AGP support in the ATI driver also has problems with this chipset - it might work for you, it might not. The best way to get around this problem at the moment is to upgrade to a 2.6 kernel, which has better AGP support and should work well with KT400 chipsets. Remember to set "UseInternalAGPGART" to "no" in /etc/X11/XF86Config-4//etc/X11/xorg.conf if you are in this situation.

Question 4.10: I'm trying to use the driver with "UseInternalAGPGART" set to "yes", but it doesn't work
Check that you don't have the kernel AGP support (see Q2.1) compiled in. If you want to use the AGP support in the driver, you should compile the kernel AGP support as modules.

The AGP support in the driver may not always work, depending on the type of motherboard and/or card that you have. It's always worth seeing what happens with "UseInternalAGPGART" set to "no". Remember to load the kernel AGP modules before you do this, or it won't work.

Question 4.11: My glxgears score is very low (<120), but everything seems to be working. Why?
You've probably enabled vertical sync while running fglrxconfig. This limits your framerate to the vertical refresh rate of your monitor, which is obviously going to affect glxgears more than anything else. To turn v-sync off, open /etc/X11/xorg.conf (or /etc/X11/XF86Config-4) in an editor, and look for the "Capabilities" setting in the "Device" section. This is a hex value, and the 3rd digit from the right controls v-sync. To turn it on, set the third digit from the right to "8", like this: "0x00000800". To turn it off, just set it back to "0" - "0x00000000".

Question 4.12: I have a Radeon 9800XT, and direct rendering doesn't work. How can I fix it?
The current versions of the driver appear to have problems with the 9800 XT, possibly because it's a relatively new card. This problem may be indicated by all 3D programs failing with a "Trace/breakpoint trap" message on startup. Until ATI fixes the driver, the best solution seems to be to add the following line to the "Device" section of your /etc/X11/xorg.conf file:
ChipID 0x4e48
and restart X.
What this does is override the chipset ID autodetection mechanism, which is normally how the type of card you have is determined. Adding this setting forces your card to be treated as a Radeon 9800/9800 Pro. This does not seem to have any impact on performance, and should allow you to run 3D applications normally.
UPDATE: I believe this problem should be fixed in all recent driver versions.

Question 4.13: I have an Epox 8RDA motherboard and can't get direct rendering to work using a 2.6 kernel
This problem appears to result from the removal of a function from the kernel source file drivers/char/agp/nvidia-agp.c. I'm not a kernel coder, so I can't tell you what the function does or why it was removed, but adding the missing function back into the file appears to get things working again without any nasty side-effects. A small patch which applies the changes can be downloaded from here. To patch your current kernel sources, perform the following commands: 
   cd /usr/src/linux
   patch -p1 < /path/to/nvidia-agp.diff
Once the patch is applied, recompile your kernel as normal, copy the new bzImage to your boot partition, and reboot.
UPDATE: this patch is longer necessary for more recent 2.6 kernels, the missing code has been added back in. You should be able to check if your kernel has it by doing grep nvidia_init_iorr /usr/src/linux/drivers/char/agp/nvidia-agp.c. If that returns a few lines of code, you shouldn't need to apply the patch.

Question 4.14: I get errors about MTRR overlaps in my logs, how can I get rid of them?
the_best_bear86 posted a fix for this problem on the Rage3D forums - Link. A more recent solution can also be found in another Rage3D posting.

Question 4.15: What does this "(WW) fglrx: No matching Device section for instance (BusID PCI:x:0:1) found" message mean?
You may see this message appearing in your XFree logs if you aren't using the secondary monitor connector on your card. X is just saying that you haven't given any configuration details for it, but this doesn't matter if you only have a single monitor in use. The "(WW)" prefix on the message indicates that it's only a warning - you can safely ignore it. Note that the number represented by the "x" will vary depending on your system.

Question 4.16: I'm using the Xorg Xserver and 3D acceleration isn't working
Before starting X, run opengl-update xorg-x11. This should get 3D acceleration working. After X is started, you can run opengl-update ati if you need to switch back to the ATI OpenGL libraries (UT2K4 requires this, for example).
UPDATE: this should no longer be necessary.

Question 4.17: Why does my system hang when I close down X?
This usually happens if you're using the Radeon framebuffer driver - try removing it from your kernel and use the VESA driver instead.

Question 4.18: I get error messages from fglrx in my dmesg output, how can I get rid of them?
If the messages mention "sleeping function", try disabling the Sleep inside spinlock checking option in the Kernel hacking section of the kernel config menu.
If you still get errors, try disabling the Hangcheck Timer option in the Character Devices section of the kernel config menu (same place as the AGP options).

Question 4.19: Do the ATI drivers support 16 bit colour depth?
No, although this is one of the requested features (see here). Until ATI add support for it, 24 bit colour is the usual alternative.

Question 4.20: I have an AMD64 system - can I use the drivers?
There are currently no 64-bit drivers available from ATI. However, the drivers should work if you're using 32-bit mode. Remember to enable the AMD Opteron/Athlon64 on-CPU GART support option in your kernel config (see Q2.1).
UPDATE: the newly released (17/01/05) 8.8.25 driver includes AMD64 support.

Question 4.21: X fails to start and the error message mentions "gnu_dev_makedev"
See the comments in this bug report (particularly the last few). You can either fix the problem manually as suggested in one of the comments, or wait for a 6.8.0 release of XOrg, which should incorporate the necessary changes.

Question 4.22: Emerging the drivers fails at "probing for VMA API version... "
This possibly indicates that you're trying to build the module for a 2.6 kernel but your /usr/src/linux symlink is pointing to an old 2.4 kernel. Check that the target of the symlink is correct (see Step 2 in Q3.1) and then emerge the drivers again.

Question 4.23: OpenGL applications fail with the error "libGL error: InitDriver failed"
This error means that you are trying to use a driver module from an old driver version with the libraries from a newer version. This usually happens if you emerge a new version without first exiting from X and unloading the old fglrx module. If you don't do this, the newly compiled driver module will not be loaded, and the old version will remain. A reboot should fix this problem if it occurs.

Alternatively, you can exit from X, unload the old module with rmmod fglrx and load the new module with modprobe fglrx. You can see the version of the module being loaded in the output from dmesg just after running the modprobe command. After loading the new module, you should be able to start X up again and have everything start working.

Question 4.24: My X server fails to start - the error is "Caught signal 11"
Try commenting out or removing the line Load "xtrap" in the Modules section of your X configuration file.

Question 4.25: X fails to start with an X300 card
If X spits out an error that mentions "cannot access V_BIOS", then this is probably caused by fglrxconfig getting a litte mixed up. Open your XF86Config or xorg.conf and find the "BusID" setting (near the bottom of the "Device" section). If the last digit is a "1", change it to a "0" and X should start working.

Question 4.26: Celestia segfaults when I try to run it
Open /usr/share/celestia/celestia.cfg with a text editor, and search for the "IgnoreGLExtensions" setting, which should be commented out by default. Uncomment it (don't change the setting itself), save the file, and Celestia should now work. There's presumably some performance hit from disabling that extension, but it still seems to run pretty well.
UPDATE: with the 8.8.25 driver, the segfaults should be gone even with the "IgnoreGLExtensions" setting commented out again. However, there is a problem with previous ati-drivers ebuilds that results in Celestia linking against the Xorg OpenGL libraries rather than the ATI libraries, resulting in poor performance. This problem has been fixed in the most recent version of the ebuild (8.8.25-r2), so be sure to upgrade if you're still using an earlier revision.

Question 4.27: How do I enable or disable vertical sync?
Follow the procedure in Q4.11.

Question 4.28: Can my CFLAGS prevent the driver from working?
Some CFLAGS may prevent the driver from operating correctly. One person has reported that using these flags: "-march=athlon-xp -O3 -pipe -ftracer -fomit-frame-pointer -frerun-cse-after-loop -ffast-math -funroll-loops -fgcse -mfpmath=387,sse -fforce-addr -frerun-loop-opt -fmove-all-movables -funit-at-a-time" will result in the loss of 3D acceleration (see here). However, this does not seem to apply to the 8.8.25 driver. If you think your CFLAGS may be causing problems, switch to a more conservative set and emerge the drivers again.

Question 4.29: Can my USE flags cause problems?
Not with the driver, but they can affect Xorg/XFree. In particular, if you are getting unresolved symbol errors in your log, and X is either failing to start or failing to enable 3D acceleration, you should check that you didn't emerge X with any of the "static", "dlloader", and "hardened" USE flags set. If you had any of these enabled, try to unset them and emerge X again.

Question 4.30: Why are all 3D applications only displaying a black screen?
If you experience this behaviour, check that the "PseudoColorVisuals" option is set to "off" in your /etc/X11/XF86Config-4 or /etc/X11/xorg.conf.

Question 4.31: Why doesn't the RANDR extension work?
To enable the RANDR extension, you must disable DGA (Direct Graphics Access). This is done by adding the following text to the "Modules" section of your /etc/X11/xorg.conf or /etc/X11/XF86Config-4:
   SubSection  "extmod"
      Option    "omit xfree86-dga" 
   EndSubSection
This text may already be in the file if you configured it with fglrxconfig, but the second line may be commented out, which enables DGA. To disable it, simply uncomment the second line.

XFCE users may find that the resolution switching system it has (which uses the RANDR extension) won't work properly if the "extmod" module is loaded, even if DGA is disabled. To prevent the "extmod" module from loading, comment out or remove all three lines listed above from your xorg.conf.

Question 4.32 (AMD64): X starts up with a corrupted screen and then locks up
If you encounter this behaviour, check that your AGP aperture size is at least 64MB in size. The aperture size can usually be altered via your computers BIOS menu.

Question 4.33: I'm using a hardened version of GCC and can't get direct rendering to work
If you have both hardened and non-hardened gcc versions installed, it is usually important to have compiled your kernel, Xorg, and ati-drivers with the same version of gcc. In addition, Xorg requires that the "dlloader" USE flag be disabled while a hardened install requires it to be enabled. The solution is to compile your kernel, Xorg, and the ati-drivers package using a non-hardened version of gcc. This problem can result in no direct rendering and the following messages in your X log: 
   (II) fglrx(0): [drm] loaded kernel module for "fglrx" driver
   (II) fglrx(0): [drm] DRM interface version 1.0
   (II) fglrx(0): [drm] drmSetBusid failed (4, PCI:1:0:0), Inappropriate ioctl for device
   (EE) fglrx(0): DRIScreenInit failed!
   (WW) fglrx(0): ***********************************************
   (WW) fglrx(0): * DRI initialization failed! *
   (WW) fglrx(0): * (maybe driver kernel module missing or bad) *
   (WW) fglrx(0): * 2D acceleraton available (MMIO) *
   (WW) fglrx(0): * no 3D acceleration available *
   (WW) fglrx(0): ********************************************* *
Question 4.34: 3D applications fail to start and/or display lots of errors about "FGLTexMgr"
See this ATI infobase article.
UPDATE: ATI have extensively reorganised their website, and this information is no longer accessible at the old location. However, the article is reproduced in the Release Notes for the current drivers, under the heading "3D Applications Produce Open of Shared Memory Object Failed Error Message".

Question 4.35: 3D acceleration doesn't work after enabling the new Composite extension in Xorg
At the moment, the driver will automatically disable direct rendering if you enable the Composite extension. This will be noted in your /var/log/Xorg.0.log file with a line like this: 
   (II) fglrx(0): Composite extension enabled, disabling direct rendering
To get 3D acceleration back, simply comment or remove the line in your xorg.conf that loads the Composite extension.

Question 4.36: Games like Tuxracer and Chromium fail to start, but 3D acceleration is enabled
If you're getting this error: "Couldn't initialize video: X11 driver not configured with OpenGL", then you probably need to emerge libsdl again with the "opengl" USE flag enabled.

Question 4.37: Why don't I have XVideo support?
If you don't seem to have XVideo support, open your /etc/X11/xorg.conf file and check the values of these settings: Question 4.38: Is there any way to fix the memory leaks in Neverwinter Nights?
If your AGP chipset works with the ATI driver's own AGP support (ie everything works with "UseInternalAGPGART" set to "yes"), then you should not suffer from this problem.

However, many AGP chipsets either are not supported or do not work correctly with the driver's own AGP support, meaning that the kernel's AGP support must be used instead ("UseInternalAGPGART" set to "no"). If you are in this situation, you should add this line to the Device section of your /etc/X11/xorg.conf: 
   Option "KernelModuleParm"  "agplock=0"
and then try Septor's fix posted here.

Question 4.39: How do I get TV-out working on a Notebook with ATI Radeon Mobility Chipset?
(thanks to Peter Maynard for this information)
The ATI drivers (v8.10.19) will allow TV-out from a notebook. However, you must disable the LCD panel before TV-out will work.

Create a copy of your /etc/X11/xorg.conf file in your home directory (make sure you don't overwrite an existing file) and edit the entries as follows: 
   Section "Device"
      Identifier "ATI Graphics Adapter"
      Driver "fglrx"
      Option "MonitorLayout" "NONE, AUTO"
      # === TV-out Management ===
      Option "NoTV" "no"
      Option "TVStandard" "NTSC-M"
      Option "TVHSizeAdj" "0"
      Option "TVVSizeAdj" "0"
      Option "TVHPosAdj" "0"
      Option "TVVPosAdj" "0"
      Option "TVHStartAdj" "0"
      Option "TVColorAdj" "0"
      Option "GammaCorrectionI" "0x00000000"
      Option "GammaCorrectionII" "0x00000000"
      ...
   EndSection

   Section "Screen"
      Identifier "Screen0"
      Device "ATI Graphics Adapter"
      Monitor "Monitor0"
      DefaultDepth 24

      Subsection "Display"
         Depth 24
         Modes "1024x768" "800x600"
         ViewPort 0 0 # initial origin if mode is smaller than desktop
      EndSubsection
   EndSection
By setting 'MonitorLayout' to "NONE, AUTO", the LCD (which is primary) will be disabled, and the TV, which is secondary will be autodetected. Make sure you boot to a console when testing this.
Attach your TV via the S-video cable and turn on the TV.
Start X using your modified X configuration file. (easiest way is to place the modified file in your home directory and run 'startx' from your home directory).
Your LCD screen wil power off and the display will output to your TV. It might not hurt to have a couple of modes available - just in case 1024x768 doesn't work.
When you stop X, the LCD will power back on and your virtual console will be visible again.

Question 4.40: X appears to be starting up, but I can only see a black screen
There are various possible causes for this. The first thing to try should always be toggling the value of the "UseInternalAGPGART" setting in your /etc/X11/xorg.conf.

Other possible solutions: Question 4.41: My card isn't detected by the driver, is there anything I can do?
There are a couple of things you can try. The first is to override the chipset autodetection that X does when it's started. You can do this by adding a line like:
ChipID 0x4e48
to the "Device" section of your /etc/X11/xorg.conf. Replace the "4e48" with the PCI ID of whatever card you want to tell X you have. The example uses the ID for a R9800 Pro. You can find a complete listing of ATI PCI ID's here.

The second thing you can try if your card has a nonstandard ID is to edit the binary part of the driver and add it in. For more information see here (look for the post by ohoiza), and here. You can try using fglrx_binary_edit to do the editing for you.

Question 4.42: I've emerged ati-drivers but I don't have an fglrx module, why?
Part of the ati-drivers ebuild attempts to compile the fglrx module against your current kernel. The other part will install various other files (OpenGL libraries etc). However, the ebuild will not fail if the fglrx module can't be compiled, so unless you watch the output closely, it's easy to miss this. The usual reason for the module failing to compile is that your kernel is too new and/or heavily patched. This often happens with the latest release candidate kernels, or patchsets like mm-sources. If you're in this situation, the easiest solution is usually to use a slightly older or unpatched kernel. For example, a vanilla-sources kernel will usually work. Also ensure that you're running the latest version of ati-drivers, as older versions are more likely to have problems with new kernels.

Alternatively, you can try searching for driver patches that will allow it to compile against mm-sources and other kernels. The best places to look for these patches are on the Gentoo forums, the Linux forum at rage3d.com, and possibly Google. If you know a little about programming, you may also be able to produce a patch yourself.

Question 4.43: X is crashing when I try to drag windows or run applications, why?
Recently, there have been a number of people reporting that enabling the radeonfb framebuffer driver in the kernel can cause these problems. If you have this driver enabled, try disabling it or switching to the VESA framebuffer driver instead.

For a more detailed investigation of the problem; see this post.

Question 4.44: I get "out of vmalloc space" errors in my dmesg output
Try adding the line:
Option "KernelModuleParm" "agplock=0"
to your xorg.conf.

Question 4.45: I have a 64-bit system and can't get 3D acceleration in 32-bit applications
Run the following command before starting the application:
   export LIBGL_DRIVERS_PATH=/usr/lib32/modules/dri

Question 4.46: How can I enable suspend/resume with direct rendering enabled?
In most cases, attempting to use suspend/resume features on laptops with the ATI driver will cause problems if direct rendering is enabled. However, it now appears to be possible to workaround this problem and allow suspend/resume functionality and direct rendering to work sucessfully.

The technique is described in this post: http://mailman.linux-thinkpad.org/pipermail/linux-thinkpad/2005-June/026968.html
The file fglrx_suspend_resume.tar.bz2 contains an example of an xorg.conf you can use as an example, and a script that performs the appropriate actions (it is intended to be executed when an ACPI lid open/close event is generated).

Question 4.47: I'm getting errors loading the GLX module after replacing an nvidia card with an ATI card
If you are in this situation, and following the installation instructions has not worked, try remerging the Xorg package.

Question 4.48: Why can't I get direct rendering enabled with AGP and PCI cards installed?
It's not clear why this doesn't work, but whatever the reason it also apparently affects the "radeon" driver, and so isn't simply a problem with the "fglrx" driver. There doesn't appear to be any way to get DRI working on the AGP card without physically removing the PCI card from the system.

Question 4.49: Why can't I get the "new-login" feature of xscreensaver to work without crashing?
At the moment, there doesn't seem to be any solution to this problem - the fglrx driver has always had problems dealing with more than one X server, and the fact that switching to the basic 'vesa' driver allows it to work suggests that it is indeed a problem with ATI's driver. The Xorg 'radeon' driver is probably the best alternative, assuming your card is supported by it.

Question 4.50: None of this stuff helped! Is there anything else I can do?
You can try posting a description of your problem in the ATI Radeon Sticky thread in the Gentoo forums. Hopefully someone will be able to help you.

If you're sure it's a problem with the driver, ATI have a feedback form on their website: http://apps.ati.com/linuxDfeedback/ - send them a description of your problem.

On the other hand, if you're sure it's a problem with the way Gentoo handles the driver, submit a bug report to bugs.gentoo.org or post your problem in the forums

Also worth checking is the unofficial ATI Linux bugzilla at http://ati.cchtml.com/. The ATI driver team know about the site, so it can be a good place to follow the progress of particular bugs that concern you.

Finally, there is now a generic (ie not distro-specific) wiki for the fglrx driver being created at http://wiki.cchtml.com.

Section 5 - Miscellaneous

Section 6 - Credits

The following people have contributed to this FAQ (in alphabetical order):