My Drupal site is slow! What can I do? - Part 1

My Drupal site is slow! What can I do? - Part 1
A brief search on Google for “slow Drupal site” doesn’t initially fill one with glee, but there are some pointers that can help prevent your Drupal site from coming to a standstill.
Firstly, some comments: if you’re here, you’ve likely got the complaint, “my Drupal site is really slow!” I’ve been where you are, and I totally understand how frustrating it can be! All the power of the Drupal framework at your fingertips and then to have it dashed by poor performance is a real pain.
Well, that assumed, let’s look at some background, what might be causing your performance issues and what you can do about it! The technical stuff is explained in another article, My Drupal site is slow! What can I do? Part 2
Firstly, compared to bespoke CMSes or maybe other Open Source ones, Drupal can be very DB intensive.
If you’re running on a shared host, this can potentially cause you some problems straight away, unless the host admins know what they’re doing. If your DB setup is no good, you’re heading for real problems.
Shared hosts have potential bottlenecks if the physical machine is hosting too many sites (or VPS units). This can make for horrible contention on the server, which will slow your page load speeds right down. This is another thing that you can check up on with your host.
Network speeds are another issue. Your host will doubtless make promises regarding availability and network speeds. However, I have found (via at least one fiasco) that you can’t always trust the figures you’re given. I have recently had to transfer some sites onto a new host because the network speed was just plain rubbish. There was no load on the server, but the delivery time of the page was topping thirty seconds (or more!) That’s a long time. In this case, finding testimonials from other users of your hosting company using the same sort of software and setup is a very wise move.
This article mainly just covers general hosting issues and caveat emptor stuff – I’ll talk a little about what you can do about these problems (or at least some of them) in My Drupal site is slow! What can I do? Part 2