While the fibre broadband coming into your house will be faster than pretty much anything you have had before, you need to be aware that the performance of the wifi or the wireless devices inside your house may not match the faster speeds of the internet coming in. The age and efficiency of the device you are using can affect the speed you see coming to the device, older devices may not have wifi cards or wired network cards that are capable of the speeds of the internet connection
The wifi signal will go as far as it can inside the house. Unfortunately the structure of the house can play a part in how far the signal can reach including the density or nature of the building materials used in the construction of the house, the size and layout of the house and indeed the location of the router in the house (ideally located somewhere fairly central but that is not always a feasible option). Solid block walls, concrete floors, foil backed insulation, underfloor heating can cause the wifi signal to weaken as it passes through. Also where possible do not put it near or behind electronic devices such as TVs, baby monitors, wireless phones, microwave ovens, house alarms, fairy lights (watch where you put your Christmas tree) as these can interfere with the wifi signal causing reduced performance.

Wifi is susceptible to interference from other wifi sources which can cause reduced performance. Some routers can dynamically change the frequency of the wifi but in some cases, this can cause the devices to momentarily drop and then reconnect to the wifi. While in most cases this would not be noticeable, some devices such as games consoles that can have persistent streams of information coming through to them, may notice breakup in the gaming experience.
Some routers add 5G to the end of the wifi name. This indicates that it is a 5 GigaHertz (GHz) signal being used for that particular wifi. The 5G that you see being touted by the mobile phone companies simply stands for 5th Generation and has no bearing on the 5G that you may see on your wifi.

5 GHz wifi is capable of much faster speed that the original 2.4 GHz wifi however it does not have the same coverage area as the 2.4 GHz wifi does. Although 5 GHz is faster, you may not be able to realise the full potential of your internet connection via the 5 GHz wifi as the performance of it is very much dependent on the performance of the wifi card inside your device. For example, if you have a 1000 Mbps fibre internet connection coming into your house, but your wireless device is only capable of 600 Mbps then you will not be able to avail of the full 1000 Mbps on that device.
Some routers have a facility to turn off the wifi on the router, thus making it look like you have no internet. If it appears that you have no internet, a quick check would be to take a mobile phone and see if your wifi name is showing up as an option for you to connect to through the phone's settings. If you are not seeing your wifi name, then it is possible that someone may have inadvertently pressed the wifi or WLAN button and usually pressing this button again will turn the wifi back on (not all routers have this option so be careful not to press any reset button on the router).
Some devices when they are left in standby can still be accessing the internet. A common culprit is games consoles doing automatic updates to the console software or to the games themselves, and some of these updates can be very large indeed. Another culprit that is becoming more popular are TV boxes. If they are left on, they will still be bringing in the stream of the TV channel, even if the TV is off.
Contention is where you have multiple users all sharing the same main connection to the internet. That can be either multiple users sharing the wifi inside the house (Wifi Contention) or it can be multiple households sharing the main connection from the local exchange to the internet (Internet Contention) or indeed it can be multiple households accessing online services (Service Contention).

Wifi Contention is caused by having multiple devices all connected to the wifi at the same time. The wifi on the router has a finite capacity and the more devices that are connected at the same time, the more that finite capacity is having to be shared amongst them all. To reduce the contention on your wifi you should switch off devices that are not being used.

Internet Contention is something over which you have no control. The maximum number of customers connected to the local exchange is governed by the owner of the exchange. They will have designed their network so that, under normal loads, there is more than enough capacity for everyone to use the internet. However there may be times where the loads on the network are higher and as a result, you could experience reduce throughput. You can think of it as being like a motorway. For most of the time there is enough space on the motorway for everyone to travel at the speeds they require (subject to the speed limits in place). However there can be times when there is more traffic on the motorway than there is space for it all to fit, and traffic then slows down (just look at the M50 at rush hour!)

Service Contention often happens when there is high demand on an online service (such as streaming services) but the service does not have sufficient capacity to handle the level of demand. Most legitimate services can dynamically increase their capacity based on the demand they are expecting however some services do not have this capability and then can be affect by demand for their service out-stripping supply.
A speed test is intended as a guide however there are a lot of factors that can affect the results that you see on screen.
  • The capability of the device on which you are running the speed test (i.e. if there are processes running in the background this can affect the result)
  • The level of usage on your connection at the time the test is being run (i.e. if your other devices are actively or passively using the internet connection then a portion of the bandwidth is being used by them which cannot then be used to ascertain the speed test result)
  • The amount of traffic on our network (i.e. at busier times, there will be more traffic on our network which could affect the results)
  • The capacity of the internet connection to which the test server is connected (test servers are hosted by various companies and some companies will have higher bandwidth capabilities that others)
  • How many other people are running speed tests to the same server as you (the more demand there is on it the more delay it could introduce to the results it is sending back)
Because there are so many factors that can affect the outcome, there is no way of guaranteeing an accurate result. There are a few things that you can do to try to mitigate some of these factors however some of them are outside of both your and our control.
  • Before running a speed test, make sure that nothing else is using the internet in your household, ideally switch off all devices so that nothing else is connected except your device
  • Make sure that the device you are using has the capability to achieve the maximum speed of your internet connection (for example do not use a laptop that only has a 100 Mbps network port on a fibre connection that can go at 500 Mbps)
  • Connect your laptop using a suitable ethernet cable, as running a speed test across the wifi can introduce other issues into the equation
  • Make sure that there are no processes running in the background on the laptop that could affect the result (for example, there are no updates running nor virus scans or other Windows processes running that could be using large amounts of processing capability of the laptop).
  • Make sure that you are running a test to a server that is located close to you (you don't want your speed test to be bouncing half way round the world and back again)
Even with these in place, it will not rule out any issues caused by high levels of demand on the network or internet from other customers.

The way in which information is packaged and transferred across the network, especially fibre connections, typically results in a loss of between 8 and 10% of the maximum capacity of the connection. This is not a fault, so speed test results will always appear to be less than the maximum available.