Here are the specifications of these RV710-based graphics cards:
Radeon HD 4550: 600MHz GPU, 1600MHz DDR3 memory, 64-bit memory bus
Radeon HD 4350: 600MHz GPU, 800MHz DDR2 memory, 64-bit memory bus
Radeon HD 4550: 600MHz GPU, 1600MHz DDR3 memory, 64-bit memory bus
Radeon HD 4350: 600MHz GPU, 800MHz DDR2 memory, 64-bit memory bus