Comparison of AMD Radeon HD 6620G video card vs AMD Radeon R7 - 512 (Toronto) video card by specs and benchmarks. AMD Radeon HD 6620G runs at 0.440 GHz base clock speed and has 1 GB of memory, while video card AMD Radeon R7 - 512 (Toronto) runs at 0.440 GHz base clock speed and has 2 GB of memory. The weight is different, -- vs --. The TDP of the first video card is --, and the second is -- . Compare the benchmark results to find out which video card is better.