Today, I will explain one of the most important type of Hosting Resource limits of Web Hosting servers, ie the I/O limit. We will put our focus on I/O limit of Shared Hosting Packages, as it is the most popular and cost effective hosting type. As you know, I/O stands for Input-Output. Let me first explain it in layman’s language.
When you are accessing a website, the content files of that site are getting transferred for rendering in your Web Browser from the Web Hosting server of that site. Web hosting servers store the content data in Hard Disks(Traditional HDD or SSD, Pure SSD etc.) and transfer them to the RAM for processing when a request(Typically a visitor on a website) comes. The limit of this Data transfer speed between HDD and RAM is called I/O Limit which is usually expressed in KB/s. Naturally, the higher is your hosting’s I/O limit, the quicker will be website loading speed and greater will be the possible number of simultaneous users.
Shared Hosting I/O Limits
In case of shared hosting servers, hundreds or thousands of websites are being run on one main server. The main server’s processor power is shared by each individual Shared Hosting Account. The main Processor has to fulfill requests of data reading and writing of each individual server which may contain many websites within it. So extremely large number of read/write operations occur between the HDD storage and RAM. In order to handle this huge workload, Hosting Providers allot a limit for I/O operation of each Shared Hosting account.
The I/O limits are configured to ensure that no single web site can collapse the entire web server which will affect every other site on the server.
When the I/O limits are exceeded your web site will start responding slower or it may simply hang. The visitor may see a “Unable to fulfill the request” or “Resource Limit Exceeded” error message. Hence it is always better to have a Hosting provider with higher resource limits, here the higher I/O limits. Many cheap web hosting providers throttle the I/O speed terribly and you are left with frequent user complaints.
Have a look at the I/o limit which is officially displayed on my Namecheap Shared Hosting Professional Plan.
The I/O speed is limited at 1536 Kilo Bytes Per second. Frankly speaking, this is very low I/O limit and I have experienced “Resource limit exceeded” error message for the websites in this account.
Next is the screenshot from Godaddy Official Page which describes different types of resource limits applicable to their hosting infrastructure.
You can see that the maximum possible I/O speed is 2MBps while for the most common Economy or Deluxe Hosting Plan, it is just 1 MBps.
Now see another screenshot from CPanel of my Hostgator Baby Plan Hosting .
Interestingly, there is no mention about the I/o limits in the Hostgator CPanel. The exact figure is nowhere mentioned in their official website also. But that does not make it worse than Godaddy or Namecheap. See my experience below.
My Experience of Hosting Resource Limits
I frequently clone WordPress websites from one domain name to another using the Duplicator or WP Clone Plugins. These plugins create a backup clone of your existing site and later on run the plugin or script on the destination server/domain name to deploy the original site.
These WordPress site cloning operation uses lot of resources. In my practical experience, I have cloned sites of size upto 230 MB using these plugins.
Unfortunately, both Namecheap and Godaddy servers crashed while trying to deploy/clone the sites. The plugins will keep on working and after 2-3 minutes a Time Out message will appear.
Thankfully Hostgator never gave such error messages and sites were cloned smoothly. It took around 45 seconds to clone a website with 200 MB content.
I discussed this with one of the support team of another Hosting Company and we experimented this process on their server and found that the cloning process was hitting the I/O limit which was causing the server to not to respond. What I understood was even though Hostgator do not publish their I/O limit openly, they either provide some higher value of I/O speed limit or use some mechanism to overcome such sudden surges in data traffic.
If you have a light weight website with moderate number of visitors, you may not be worried about the hosting resource limits, particularly the I/O limit. But if your site grows further with lot of content and visitors, many of the Shared Hosting plans can not handle it and your customers will experience sluggish navigation on your site. Hostgator is an exception here. An ordinary Shared Hosting server at Hostgator can handle 30K monthly visitors without any issue. So I never experienced sluggishness on my sites hosted at Hostgator and happily recommend them to all.
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