nginx ssl performance

[huakaibird]

Hi,

I want to test the nginx server performance with different server
configuration (CPU and RAM etc)

I first use apache ab as testing tool, nginx server with 2 CPU and 4G RAM,
http test could handle 7000 requests/s, cpu usage reach to 30%-40%. But
https' performace drop dramatically to only 300-400 requests/s and cpu usage
reach to 100%.

Then I also use jemeter and wrk to test, find https' performance is not so
much less than http, it's only a little than http. For example use wrk test
http, can reach to 5300 requests/s, while https could reach to 5100
requests/s and CPU almost same, will not reach to 100%.

So I'm confused, is that because the test tool ab's problem, if it's ab's
problem, why it's http performance is good? 
If ab's test result is correct, is https' performance is so bad than http?

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,265046,265046#msg-265046