Test results: GPU performance
Nenamark and GLBenchmark are test programs that put a heavy load on the graphical side of a smartphone or tablet. Each device runs the benchmarks in their native resolution. This puts the phones with a higher resolutions at a disadvantage, but does provide a good indication of real-life performance, since actual applications also run in their native resolution.
The benchmarks show that the GPU in the Samsung Galaxy S III Mini is powerful enough for its display. The offscreen test shows that it doesn't have a lot of raw computing power.