How important is IOPS for web hosting?
Web hosting performance can be measured by anyone of several metrics - total disk space and bandwidth allowance perhaps being the most common examples.
This is a useful approach as it helps to define the boundaries you'll be working in as a hosting customer, but they don't provide information about how quickly you can perform a particular task or the overall speed and responsiveness you experience. For this, we'll need to focus more on the hardware specifications and management of the hosting server itself.
In this post I'm going to look at a particular performance measurement which was commonly overlooked, particularly in comparison to processing and RAM specifications. However seems to be cropping up with a little more regularity, and that is IOPS, or input/output operations per second, a measurement specific to storage devices, both HDD and SDD, and obviously an integral component of a hosting server.
How It Works
In straightforward terms IOPS is a measure of how quickly a storage device can read (retrieve) or write (store) data to the hard drive. How this works with regards to loading your website, for example, is the IOPS determines how quickly the information which is stored on the hard drive can be retrieved and delivered to the loading powerhouse of the RAM for assembly.
(Random throughput (IOPS) of a X25-E SSD vs. HDD 7200 RPM - ResearchGate.net)
To give you an example, a traditional SATA hard drive might have had an IOPS value in the range of tens to hundreds (for convenience sake imagine 50 - 200) depending on the manufacturer and specification of the device. By comparison, this value for an SSD device can easily reach into the multiple thousands, vastly quicker than even the best performing HDD. This is why web hosting companies spare no expense advertising the fact that they use SSD's if they do so.
So you'd assume that with all things being equal a web host whose servers use higher IOPS storage devices would provide a higher performance hosting products. This might be true but then again it might not.
As with any measurements you take from a relatively complex, multicomponent system the overall importance of a single value depends heavily on whether its performance limiting factor or not, i.e. as long as there are no other bottlenecks further down the line. Following on from the previous paragraph, if your server has insufficient RAM to handle the information delivered to it from the hard drive then IOPS is not limiting the performance (obviously the RAM is), the same holds true for processing if the processor were unable to keep up with demand.
So the reality is that to get the best performance out of your server and therefore your web hosting plan you need to establish/maintain a balance between processing, RAM, and IOPS such that each performance variable works synergically with the others without overwhelming the weak link leading to a performance bottleneck. However, if the server infrastructure of your hosting provider has an excess of RAM and processing resources available then higher IOPS hard drives could yield a more powerful hosting experience.
This article is written by Tom from WebHostGB. WebHostGB.com are a web hosting and design company based in the north of England who specialise in providing high performance shared hosting, and all inclusive design and hosting packages for business.