Comparison of AMD Radeon HD 8450G video card vs AMD Radeon HD 7640G video card by specs and benchmarks. AMD Radeon HD 8450G runs at 0.530 GHz base clock speed and has 2 GB of memory, while video card AMD Radeon HD 7640G runs at 0.530 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.