It is commonly known by data networking technicians that a wired network for Internet connectivity is faster than Internet connectivity from a wireless router. But what is not commonly known is why. A router is a device that is used to connect one network, such as the Internet, to a Local Area Network (LAN) that has several connected devices such as computers. Wired Local Area Networks commonly use the Ethernet protocol for data communications. This protocol generally has bandwidth speeds from 10Mb/s (megabits per second) to 1000Mb/s with 100Mb/s being the most commonly used for networking computers in most homes and offices. The Ethernet data communication protocol uses full-duplex communication; that is, it can send and receive data at the same time.
Internet Service Providers mostly offer high speed broadband services up to 1.5Mb/s which are defined in terms of the maximum download speed because several common consumer broadband technologies have a slower maximum upload speed.
A router as the name implies, distributes data packets from the Internet to each requesting computer connected to it. This is done in an orderly manner by using high speed electrical switches. The maximum rate at which the router can switch the data packets also determines the maximum speed of operation of the Local Area Network. If you have too many computers connected off the router, the router can become a speed bottleneck. So in theory, if you use a 100Mb/s Ethernet cable to connect to your Internet Service Provider, then your Internet connection will not slow down as most broadband Internet Services for home use peak out at around 1.5Mb/s, and business use peaks out at about 10Mb/s (but shared across many computers).
With wireless data networks, the most widely used protocol is the IEEE 802.11 standard. This standard has had many revisions over the past few years and the latest is the 802.11n version. The 802.11n version can in theory work up to 300Mb/s whereas the earlier 802.11b version works up to 11Mb/s and the 802.11g works up to 54Mb/s. But wireless routers only provide wireless data connectivity using a half-duplex protocol (either send or receive data but not both at same time) and this makes them slower than wired Ethernet connections. But there are a few other factors that make wireless networks slower than wired networks due to signal and data processing overheads. The wireless signal can be susceptible to local interference from other nearby electrical equipment and this can cause the performance of the wireless network to degrade. When the wireless signal degrades, the wireless router must perform more data error corrections to maintain the integrity of the data and this causes delays in distributing the data to and from its destination and slows down the connection.
If wireless security protocols are also used to encrypt the data, this requires additional data processing to be undertaken that can also limit the performance by introducing inherent latency delays. Hard-wired networks do not need to have the data packets encrypted because they are physically secured in most buildings whereas wireless networks cover areas that are not secured and hence the data needs to be encrypted to secure it from unauthorized users.
For better performance Internet connectivity, use a wired cable if you can because it is physically secure, allows faster performance, costs less, and is not as susceptible to electrical interference compared to wireless connectivity.
In summary, if you use your computer for gaming, voice over IP, or real-time collaboration, then you are better off using a wired cable network connection to the router that connects to the Internet Service Provider.