You’re sending 1500 byte MTU (1538 bytes on the wire) or maybe larger (9000 byte MTU) packets. 1538 bytes is 12,304 bits. 10,000,000,000 bits/sec / 12,304 bits

You’re sending 1500 byte MTU (1538 bytes on the wire) or maybe larger (9000 byte MTU) packets. 1538 bytes is 12,304 bits. 10,000,000,000 bits/sec / 12,304 bits/packet is 812,744 packets per second. Now try it with 64 byte packets, which are 84 bytes on the wire. 14,880,952 packets per second. And this is 10gbps.