SSL Speed: 128 vs 256 bit

Question

I've decided to encrypt my entire site with SSL, even if only parts of it are actually necessary. End result being that the site is now a bit slower. So, my questions are:

1. Should I have only encrypted the members section of the site (keeping in mind I do have login forms on the frontpage)?
2. Should I perhaps decrease the encryption to 128 bit?

Is the speed difference significant if the site is generally small?

And then, does anyone know of a good site or method that you can see the true speed of your site SEVERAL TIMES IN A ROW? i.e. so caching doesn't mess with your results?

Answer 1

The key size isn't likely to make much difference to the overall speed. Using SSL will indeed put your web server under more load (the server has to encrypt all traffic including images, and the initial connection handshake is more involved). This shouldn't be a big problem if your site is generally low-traffic.

You can use SSL just on the private sections; just be sure that the login form is served over https and/or submits to an https url.

Good benchmarking tools will probably depend on your platform. If you're on linux, you might try the 'ab' command which comes with apache.