It's more complicated, but you can get the exact video card name with ADL.
Or with OpenCL you can get the chip's name (eg. 'Tahiti').
With ADL you have to initialize with
And you can get the number of devices with ADL_Adapter_NumberOfAdapters_Get
Then finally you can get the info for all the devices with ADL_Adapter_AdapterInfo_Get.
The strAdapterName field will contain correct names, like HD6970 or HD7770. Not just that 'HD7900 series' thing which is rather the name of the driver.