Yes it will. It is additional computing effort and naturally it will use more resources. But it's only a very tiny fraction of the total request processing time.

You won't lose the benefits of caching. Server side caching is all about how you have designed your application. Browsers cache content even if they are delivered through https.

I haven't developed 'high-traffic' applications in their general sense. But in the applications that I have developed so far, I could not observe any difference at all in performance or user experience.

Also, if my application does suffer any performance loss because of SSL, security would still be my priority over performance.

For all practical purposes, I don't care about the performance overhead of SSL - I see it this way, you either take it or leave it and for all modern websites, leaving it is not an option.

Thanks to the distributed nature of modern applications, I can just throw more hardware at it when the number of users goes over my serving capacity.

I just googled your question cause nobody answered it here.

I found an interesting anwswer to your question on StackOverflow: stackoverflow.com/questions/149274/http-vs-https-…

As it is written there, it depens on many things like:

• Hardware
• Server software
• Ratio of dynamic vs static content
• Client distance to server
• Typical session length
• Etc
• Caching behavior of clients

Hope this might help answer your question or bring a little idea what happens if you enable ssh.