Now that we offer a wider range of dedicated servers, you may find it hard to decide exactly what’s right for your needs. Single or dual-processor? How much RAM? What types of disks? Here’s some more in-depth information to help you make a decision!

1 processor or 2? 

Our new dedicated servers offer 2 x quad core CPUs – that’s a total of 8 cores of processing power. The trend over the last few years has been for manufacturers to produce processors with more cores rather than faster clock speeds, which makes it a bit more important to understand how your application works in order to make a decision. A lot of workloads can be split up into multiple concurrent processes, each of which can benefit from having a core to itself rather than waiting for scheduled time on a single core – for example, a typical Linux web server will be running database queries, executing PHP scripts, running an Apache thread per open connection and maybe running crons at any given point in time – there’s little advantage in running each of these any faster as they each have to wait for each other, but by allowing them to run in parallel, they can complete in the fastest time possible.

If you already have a server or VPS and find that the load average regularly exceeds the number of cores in the machine, then you’ll probably benefit from upgrading – the load average figure is the number of processes running or waiting for spare CPU cycles to run at any one time. If you’re planning a new application, then it’s worth considering how many cores you need to avoid bottlenecks in your application.

How much RAM do I need?

A server uses RAM for several purposes – as well as storing data required by running applications, modern operating systems use free RAM to cache data from disk (speeding up disk operations) and often make use of in-memory virtual disks to provide shared temporary file storage for applications. In general, you should ensure that you have sufficient RAM for all the programs that you need to run simultaneously, and sufficient left over for disk cache; on our shared web hosting servers, we aim for a 50:50 split between application memory usage and disk cache. Once you’ve got your server set up, it’s important to configure your applications to make the most of the memory available – the defaults for many common server applications are very low. If you’re running VMs on your server, don’t skimp on the RAM – you should ensure that you have sufficient for each guest OS to use its entire allocation, and have sufficient left over for your host OS to operate.

SATA or SAS disks?

What about RAID cards?

You’ll notice that all our servers have hardware RAID cards – this does mean that they’re not the cheapest servers on the market, but we believe in delivering a quality product. It’s possible to use software RAID but this can be very difficult to recover from and there’s a performance overhead – every write that’s made to the disk incurs addition work for the main CPU, which could be used for making your application faster! We offer hardware RAID cards to take the strain of handling disk i/o operations, and our top-end servers use Dell PERC H700 cards with 4 drives to give maximum i/o performance and full redundancy.

When choosing a dedicated server, it’s important to be both honest with yourself about your needs and realistic about the capabilities of your selected server. We don’t hold you to a long contract, so you should typically purchase the server that will meet your realistic expectations in 6-12 months’ time – you can always purchase additional servers or upgrade if things go much better than expected. Do you really need 2TB of storage from day one for your latest project, or will it take a while to grow to that? Likewise, overworking too low-spec a server is a false economy that leads to a poor experience for your users and ultimately hurts your business – if you need high-performance hardware to keep your site snappy and responsive, then don’t be afraid to take the plunge.