BITS is the size of the RSA key being used on the server, and SECONDS is the average amount of time it took for `openssl s_client` to finish. I assume this translates to the length of time an SSL connection takes to deal with the SSL part and start exchanging data.

BITS	SECONDS
1024	0.07
2048	0.16
3072	0.32
4096	0.47
5120	0.78
6144	1.28
7168	1.95
8192	2.83

Server: Raspberry Pi with dynamic overclock to 1.1 GHz, running ZNC on Raspbian
Client: Phenom II 3.3 GHz running OpenSSL on Cygwin (going via Windows's `netsh interface portproxy` because `openssl` STILL DOESN'T DO IPV6 ARGH)

(As a reminder to myself, the specific command was:
  TIMEFORMAT="%R"; (for x in {1..30}; do ( time openssl s_client -connect localhost:60000 <<< "^D" > /dev/null 2>&1 ) 2>&1 ; done)
(the ^D needs to be a literal ^D).)