There can be many possible reasons why a web site is slow. Here are the list of possible causes:
- The server is slow or overloaded. This is the most common thing to be blamed.
- The web site has design elements that causes it to be slow, e.g. large images, large amount of js, css, images to be loaded
- The web site is loading external elements that are slow
- The web side code (php, asp.net, perl, etc) is inefficient. There may be many reasons for this too, such as
- Bloated, inefficient plugins
- Too many plugins to execute
- Too many 404 objects handled poorly. See this article: https://support.quadrahosting.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=226
- Bloated database, e.g. hundreds of thousands of spam comments stored in the database, or thousands of post revisions never cleaned up.
On this article, we will address the first issue, as it is the only thing that is relevant to us. The other problems are within your control to change and not ours.
On a shared server, your site shares the server resources (time, cpu power, memory, disk access, etc) with hundreds of other web sites. This model is called "shared hosting" and it provides a cost effective means of hosting your site. However, the performance of your site and the server is subject to the demands of these several hundred other web sites. If your "neighbour" on the same server happens to be busy, the server will be busy and will have less time to execute your code.
While there are innovations such as Cloud Linux to ensure that no single web site can monopolise the entire server, the fact remains that on a shared server, your web site only gets a fraction of the cpu time that the server can provide, and when other sites are busy, your web site will still suffer.
Quadra Hosting utilises CloudLinux on some of our servers, however we find that it is not the silver bullet in addressing this issue.
If the slowness is indeed caused by the server, we can offer several alternatives:
- Move your account to another shared server with better "neighbours". Not all web sites are busy and highly popular. We have hundreds of servers and some are busier than others. We can pick another server that's less busy and move you there. This option does not cost you any extra. For more info on this option, see: https://support.quadrahosting.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=163
- Upgrade your account to a virtual server, where your site will be the only tenant on the server. You will not have to compete against other web sites and you will notice a significant performance improvements. For more info on virtual server, see: www.quadrahosting.com.au/virtual-server/