Kafka has a good throughput with sequential Writes and Reads.

Kafka can move a lot of data because of the zero copy read principle:
Before:

1. Disc to OS buffer
2. Write the content of the OS buffer to the RAM
3. Copy the data to the application Buffer
4. Copy the data back to the socket buffer
5. Copy the data from the socket to the Network Interface Chip buffer and send it

With zero-copy read principle:

1. Read from the disc and load it into the OS Buffer
2. Directly copy to the NIC Buffer (the CPU is not involved)