I don't believe that FLOPS correlates very well to mining speed since I believe that mining relies more on integer math. But that being said a standard Radeon 7970 does about 4000 GFLOPS. I don't think the effort required to get your DSP card to work would be worth the time unless it's just for fun.

http://en.wikipedia.org/wiki/List_of_AMD_graphics_processing_units