How can I get a two-display Radeon HD 3470 graphics setup working with Scientific Linux 6.5?

I have Scientific Linux 6.5 (2.6.32-431.11.2.el6.x86_64) installed on a Dell OptiPlex 760 with a Radeon HD 3470 graphics card and two displays hooked up to it. I'm having difficulties setting resolutions appropriate for the displays and having the two displays not show the same screen. I am not an expert in Xorg configuration and I would appreciate some assistance in getting things working. The PCI device listing (

| grep VGA

) for the graphics card is as follows: 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV620 PRO [Radeon HD 3470] A more detailed listing (

-v -s $(lspci | awk '/VGA/{print $1}')

) is as follows: 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV620 PRO [Radeon HD 3470] (prog-if 00 [VGA controller]) Subsystem: Dell Device 3243 Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at d0000000 (64-bit, prefetchable) [size=256M] Memory at fe9f0000 (64-bit, non-prefetchable) [size=64K] I/O ports at dc00 [size=256] Expansion ROM at fea00000 [disabled] [size=128K] Capabilities: Power Management version 3 Capabilities: Express Legacy Endpoint, MSI 00 Capabilities: [a0] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: Vendor Specific Information: ID=0001 Rev=1 Len=010 Kernel modules: radeon The result of an

query (

-q

) is as follows: xrandr: Failed to get size of gamma for output default Screen 0: minimum 640 x 400, current 1280 x 1024, maximum 1280 x 1024 default connected 1280x1024+0+0 0mm x 0mm 1280x1024 0.0* 1152x864 0.0 1024x768 0.0 800x600 0.0 640x480 0.0 720x400 0.0 The modeline returned by the coordinated video timing utility

for the highest resolution capable by the main display (1680 x 1050) is as follows: cvt 1680 1050 # 1680x1050 59.95 Hz (CVT 1.76MA) hsync: 65.29 kHz; pclk: 146.25 MHz Modeline "1680x1050_60.00" 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync If I try to use this with xrandr, I get the following: xrandr --newmode "1680x1050_60.00" 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync xrandr: Failed to get size of gamma for output default The entire contents of the /etc/X11/xorg.conf file is as follows: Section "Device" Identifier "Videocard0" Driver "vesa" EndSection I am not sure what to do next in order to get the appropriate resolutions set and to get the two displays working as two separate displays (as opposed to having the mirror behaviour). --- UPDATE: I have attempted to install a driver for this graphics setup (

-8.97.100.7-1.x86_64.rpm

), but have run into difficulties regarding undefined symbol

. The ending contents of the file

.0.log

are as follows: [ 39.312] Initializing built-in extension XVideo [ 39.312] Initializing built-in extension XVideo-MotionCompensation [ 39.312] Initializing built-in extension SELinux [ 39.312] Initializing built-in extension XFree86-VidModeExtension [ 39.312] Initializing built-in extension XFree86-DGA [ 39.312] Initializing built-in extension XFree86-DRI [ 39.312] Initializing built-in extension DRI2 [ 39.312] (II) "glx" will be loaded by default. [ 39.312] (II) LoadModule: "glx" [ 39.338] (II) Loading /usr/lib64/xorg/modules/extensions/libglx.so [ 39.358] (II) Module glx: vendor="Advanced Micro Devices, Inc." [ 39.358] compiled for 6.9.0, module version = 1.0.0 [ 39.365] Loading extension GLX [ 39.366] (II) LoadModule: "fglrx" [ 39.366] (II) Loading /usr/lib64/xorg/modules/drivers/fglrx_drv.so [ 39.520] (EE) Failed to load /usr/lib64/xorg/modules/drivers/fglrx_drv.so: /usr/lib64/xorg/modules/drivers/fglrx_drv.so: undefined symbol: noXFree86DRIExtension [ 39.520] (II) UnloadModule: "fglrx" [ 39.520] (II) Unloading fglrx [ 39.520] (EE) Failed to load module "fglrx" (loader failed, 7) [ 39.520] (EE) No drivers available. [ 39.520] Fatal server error: [ 39.520] no screens found [ 39.520] (EE) Please consult the Red Hat, Inc. support at https://www.redhat.com/apps/support/ for help. [ 39.520] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information. [ 39.520] (EE)