From time to time we get asked “If I use SSL – won’t it affect my Moodle’s performance?” – this is a great question.
We see the use of SSL growing across the web (i.e. Banks, Cloud-based Services, Email services, Youtube, Twitter, Google, Facebook…,etc), and there are some good reasons for doing this: encrypting your web-traffic helps to secure data; gets your site a higher ranking from Google; and most importantly – it helps to protect your users’ data.
It would be untrue to say that moving to use full HTTPS (that is across the entire site) doesn’t have any effect, however it is very very minor. In the past older systems and architectures did present with additional load and system resource requirements; however with modern systems alongside modern browsers the effect is essentially negligible. To examine this in a bit more detail, I took one of customer’s system performance data and have graphed it below:
The customer is a fairly large customer, and there is essentially no difference between the performance before and after having HTTPS implemented on the system.