The smallest Ethernet frame is 512 bits,
so at 1 Gbps we get 1,953,125 or almost 2 million frames/sec.
However, this only works when frame bursting is operating.
Without frame bursting, short frames are padded to 4096 bits, in which case the maximum number is 244,140.
For the largest frame (12,144 bits), there can be as many as 82,345 frames/sec.