With the fglrx 8.39.4 driver (or newer), there's a chance you may run into a watermark (similar to the AMD testing watermark) saying that your hardware is unsupported when in fact it is supported. If you run into this unsupported hardware watermark, it's likely that /etc/ati/control is missing. If that's the case for you, try reinstalling the driver or manually copying the control file. The driver contents can be extracted using the --extract argument and the control file is located in common/etc/ati/. If you experience this problem, create a thread in the Phoronix Forums with what distribution you are using and how you had installed the driver initially (and whether adding the control file had removed the watermark).