Thanks! I didn't know nginx sucked at SSL. You may have increased our revenue. Many businesses like us have our conversion pages on SSL. Our front-end server is doing 2000 to 4000 http requests per second and we get over 3 million uniques on the main site where we sell stuff via SSL. If SSL is this slow, it probably impacts performance on our secure pages which affects revenue. Where do I send the beer?

On a 4 core Xeon E5410 using ab -c 50 -n 5000 with 64 bit ubuntu 10.10 and kernel 2.6.35 I get:

For a 43 byte transparent gif image on regular HTTP:

Requests per second: 11703.19 [#/sec] (mean)

Same file via HTTPS with various ssl_session_cache params set:

ssl_session_cache shared:SSL:10m; Requests per second: 180.13 [#/sec] (mean)

ssl_session_cache builtin:1000 shared:SSL:10m; Requests per second: 183.53 [#/sec] (mean)

ssl_session_cache builtin:1000; Requests per second: 182.63 [#/sec] (mean)

No ssl_session_cache: Requests per second: 184.67 [#/sec] (mean)

The cache probably has no effect because each 'ab' request is a new visitor. But I'd guess the first https pageview for any visitor is the most critical pageview of most funnels.