Why isn’t my Wi-Fi as fast as advertised?

When shopping for a new router, it’s important to understand the data behind Wi-Fi performance. While Wi-Fi technology has advanced significantly, many users still find that their actual speeds don’t match the advertised rates. This FAQ explains why this happens and what factors influence your Wi-Fi speed.

1. Understanding Data Rate and Throughput

To evaluate wireless network performance, two key terms are often used: data rate and throughput. While they are related, they measure different aspects of your connection.

Data Rate (Physical Rate):
This is the maximum theoretical speed between your router and a connected device over a wireless link. It represents the internal WLAN (Wireless Local Area Network) connection speed, not the actual internet speed. In real-world scenarios, the actual transmission speed is typically 75% or less of the advertised data rate due to factors like distance, interference, and device limitations.

Throughput:

This is the actual speed available for applications after accounting for overhead (e.g., protocol requirements, security, and network management). Throughput is always lower than the data rate and is a more accurate measure of the usable speed you experience.

2. Factors Affecting Actual Wi-Fi Speed

Wi-Fi performance can vary significantly due to several factors. Here are the most common ones:

1) Environment and Distance

Wireless signals weaken over distance and struggle to penetrate solid objects like walls or floors. This is especially true for 5 GHz Wi-Fi, which offers faster speed but has shorter range and poorer penetration compared to 2.4 GHz Wi-Fi.

What You Can Do:

Place your router in a central location, away from obstacles, and closer to where you use your devices most.

2) Connected Devices

Number of Devices:

Wi-Fi is a shared medium, meaning all connected devices compete for bandwidth. Too many devices can slow down the network.

What You Can Do:

Check your router’s recommended device limit and avoid overloading it. Consider upgrading to a router with higher capacity if needed.

Legacy Devices:

Older devices that support only slower Wi-Fi standards (e.g., 802.11b/g) can drag down the entire network. This is because routers communicate with one device at a time, and slower devices take longer to transmit data.

What You Can Do:

Avoid using too many legacy devices. Enable Airtime Fairness (if supported by your router) to allocate bandwidth more efficiently.

3) Interference

Wi-Fi signals can be disrupted by other wireless networks, household devices (e.g., microwaves, Bluetooth devices, or USB 3.0 ports), and even neighboring routers using the same channel.

What You Can Do:

Switch to a less crowded Wi-Fi channel or use the 5 GHz band, which is typically less congested than the 2.4 GHz band.

4) Other Limitations

ISP Bandwidth:

Your internet speed is ultimately limited by the plan you subscribe to. Even with a high-performance router, you won’t exceed the speed provided by your ISP.

Router Power Supply:

An inadequate power supply can cause your router to underperform. Ensure your router is using the correct power adapter.

3. Do You Need a Router with a Higher Data Rate?

It depends on your needs:

For Most Users:

Modern routers with mid-range specifications are sufficient for everyday tasks like browsing, streaming, and gaming.

For Tech Enthusiasts or Heavy Users:

If you have the latest devices (e.g., Wi-Fi 6/Wi-Fi 7 smartphones or laptops) and require high-speed data transmission (e.g., 4K streaming, large file transfers, or online gaming), a router with a higher data rate is recommended. Higher data rates also provide better performance in challenging environments.