This is because they don’t really understand the multitude of factors that can impact Internet performance, and are therefore  left disgruntled with their Internet service provider (ISP). So what’s going on here?

Some of the misunderstanding can perhaps be traced back to the days of ADSL, when the line was the bottleneck and Internet users became accustomed to upgrading the pipe to get better performance – typically going from a 1Mbps line to a 4Mbps to a 10Mbps line and so on.

However, in the Fibre era, where we are seeing pipes of 50 to 100Mbps, or even 1Gbps, the line is no longer the bottleneck.

Many speed testing platforms have their limitations and either use the incorrect methodology, or overlook important aspects that impact the quality and performance of your connection to the Internet.

Understanding capacity and throughput

Firstly, it is important to understand the difference between capacity and throughput. Capacity – popularly known as bandwidth – is what ISPs sell, and it is a measure of the amount of data per second (Mpbs) that a communication link can transport. Throughput, on the other hand, is the actual amount of data that is successfully sent or received over the communication link.

Speed tests measure throughput and not capacity, and there are a number of constraints in the system that prevent throughput from ever reaching capacity levels.

For instance, the architecture of some laptops – even if not connected to the Internet via WiFi, but to the router via a cable – is simply not designed to get to 1Gbps. In addition, the way it is set up, the CPU, the operating system, browsers and antivirus software all impact throughput speeds.

Another basic mistake that people make is performing a speed test over WiFi, forgetting that the farther they are from their access point, the lower the link capacity. Consequently, as you move further away from your access point, WiFi throughput also drops rapidly and becomes your overall limiting factor, especially on faster line speeds.

Choosing the right server and latency

Some speed testing services geo-locate users by their IP address and then automatically selects the ‘closest’ server when running a test. Unfortunately, their logic is somewhat broken.

Instead of constraining their server selection to ensure it’s connected to the users’ ISP network, they just choose any server, regardless of the ISP network it’s connected to. You then end up with situations where a user in George (for example), whose Fiber access circuit first touches his ISP’s network in Cape Town, runs his speed test to a small WISP’s server in George with only a 50Mbps Internet connection.

In this example, the customer will need to manually override the auto-selection and choose to instead run the test to a server in Cape Town, in order to get a more realistic result.

Yet, the bigger issue is that of latency, which is determined by the overall path (routers and interconnecting links) that IP packets and signals traverse, and is a huge factor in TCP/IP performance. TCP, part of the TCP/IP communications protocol, performs end-to-end error checking of data transmission for reliable and sequential exchange of data.

Back in the 1970s, when the protocol was invented, latency wasn’t an issue, but that’s all changed now, and the protocol itself is a limiting factor.

Keep in mind that while the primary job of the internet’s routers and that of your ISP is to route IP packets, it’s the end-users’ devices and applications and content providers’ servers that chooses to use a protocol (TCP) that now constrains throughput performance to levels lower than the link capacity. There is nothing your ISP can do to fix this.

Bigger highway, but the same car

Think of it this way. Your car is constrained through its design, aerodynamics and engine performance to achieving a top speed of say, 200km/h when driving down a road with a single lane.

If we now upgrade that same road to four lanes, can your car now do 800Km/h? No. It can still only achieve 200km/h. But you can now have four cars, each driving at 200Km/h driving down the road at the same time. The same situation occurs over fast Internet links.

Most consumers are totally unaware of the above factors and do not understand that the ‘results’ they get when using one of the many speed testing websites, will vary significantly based on server selection, the mathematical algorithm, process and protocol used to calculate the speed, browser or app technology being used.