As you can plainly see from this graph, my TPM chip can do approximately 1.4 SSL handshakes per second. A handshake takes about 0.7 seconds of TPM time, so when two clients are connecting the average connect time is 1.4 seconds. This means probably not useful on server side, but should be good for some client side applications.
To replicate the test, start a server:
openssl s_server -keyform engine -engine tpm -accept 12345 -cert foo.crt -key foo.key -tls1 -CAfile foo.crt -verify 1 -status
And then connect 100 times:
for n in $(seq 100); do time openssl s_client -tls1 -connect localhost:12345 < /dev/null >/dev/null 2>/dev/null;done 2> timelog
Then just look at the “real” time in the timelog. (if in doubt, use bash. zsh gave me some crap in the log) Example GNUPlot:
plot [1:] [0:2] '2' using (2/$1) w l title '2 clients','1' using (1/$1) w l title '1 client'