Larger caches and compression as well as considerably higher memory clocks enable them to reduce the bus width whilst being able to hit the performance target.
Both the 2070 and 3070 have a memory bandwidth of 448GB/s the 4070 with its smaller bus has a memory bandwidth of 504GB/s.
Both the 2070 and 3070 have a memory bandwidth of 448GB/s the 4070 with its smaller bus has a memory bandwidth of 504GB/s.