What version of that distro are you using?
The exact model of mobility raedon would help a lot as well. You can find that out various ways, lscpi is easy.
You just open a terminal and enter 'lspci' then post the results here. In 'code' tags is best, it makes the forum neater. you can find the 'code' tags by going to the control area about the posting area, its the '#' symbol.
Here is what it should look like-
Code:
00:00.0 Host bridge: ATI Technologies Inc RX780/RX790 Chipset Host Bridge
00:02.0 PCI bridge: ATI Technologies Inc RD790 PCI to PCI bridge (external gfx0 port A)
00:09.0 PCI bridge: ATI Technologies Inc RD790 PCI to PCI bridge (PCI express gpp port E)
00:0a.0 PCI bridge: ATI Technologies Inc RD790 PCI to PCI bridge (PCI express gpp port F)
00:11.0 SATA controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode]
00:12.0 USB controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:12.1 USB controller: ATI Technologies Inc SB7x0 USB OHCI1 Controller
00:12.2 USB controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:13.0 USB controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:13.1 USB controller: ATI Technologies Inc SB7x0 USB OHCI1 Controller
00:13.2 USB controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:14.0 SMBus: ATI Technologies Inc SBx00 SMBus Controller (rev 3c)
00:14.1 IDE interface: ATI Technologies Inc SB7x0/SB8x0/SB9x0 IDE Controller
00:14.2 Audio device: ATI Technologies Inc SBx00 Azalia (Intel HDA)
00:14.3 ISA bridge: ATI Technologies Inc SB7x0/SB8x0/SB9x0 LPC host controller
00:14.4 PCI bridge: ATI Technologies Inc SBx00 PCI to PCI Bridge
00:14.5 USB controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB OHCI2 Controller
00:18.0 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor HyperTransport Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Miscellaneous Control
00:18.4 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Link Control
01:00.0 VGA compatible controller: nVidia Corporation G84 [GeForce 8600 GT] (rev a1)
02:00.0 USB controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)