[anonymouscowar1]

> four million packets per second (well, one million until I parallelize), which is about 85 megabytes per second

Why is this more than 4 million bytes per second (4 MB/s)? A packet can contain a single byte.

[kragen]

To be a valid TCP packet, it needs to contain at a minimum a 20-byte IP header and a 20-byte TCP header, plus the one byte of payload. In practice your server is probably receiving the packet over Ethernet, so it probably has an Ethernet header and things like that, too, but that's a minimum. You could approach it over, say, SLIP.