Comparison of AMD Radeon HD 7400G video card vs AMD Radeon HD 6620G video card by specs and benchmarks. AMD Radeon HD 7400G runs at 0.330 GHz base clock speed and has 1 GB of memory, while video card AMD Radeon HD 6620G runs at 0.330 GHz base clock speed and has 1 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.