Does a Web site run any slower if all pages are accesses as SSL?


My question is will a Web site, with high traffic, run any slower if we force all pages to be SSL secure?
That is will there be any extra load on the server for all pages being SSL secure?


The speed difference is negligible. Most of the load goes to the visitors CPU, but it’s very low. There could be some problems if you are using limited resource system (like mobile phone) to load the website, but nowadays they are quite fast also. Also encryption could make caching an load balancing much harder, this could have some performance penalty.

Browsers will cache content regardless of the protocol used (HTTP vs HTTPS) unless you specifically tell the browser not to do so.