--- title: "Part 4: Wi-Fi Speeds: Theory vs Reality" description: The gigabit speed on your router’s box is a theoretical maximum, not a promise. Here is why real-world Wi-Fi speed is always lower, and why that’s normal. image: https://homenetworks.com.au/hubfs/wifi-blog-theory-v-reality2.png --- [Skip to content](https://homenetworks.com.au/smart-home-networks-and-iot-blog/part-4-wi-fi-speeds-theory-vs-reality#main-content) ![SMH&I](https://homenetworks.com.au/hs-fs/hubfs/Logo%20Transparency%20-01-300px.png?width=300&height=127&name=Logo%20Transparency%20-01-300px.png)Homepage - Home - Products & Solutions - Networking - [Aruba Instant On](https://homenetworks.com.au/network/hpe-aruba) - [TP-Link Omada](https://homenetworks.com.au/network/tplink-omada) - [HPE Juniper Networks](https://homenetworks.com.au/network/hpe-juniper) - Smart Home Controllers - Home Assistant (HAOS) - openHAB - [NUC Build Configurator](https://homenetworks.com.au/smart-home-hubs) - Cameras & Security - IoT Devices - Guides - [What is a smart home](https://homenetworks.com.au/guides/what-is-a-smart-home) - [The building blocks](https://homenetworks.com.au/guides/smart-home-building-blocks) - [Connectivity](https://homenetworks.com.au/guides/smart-home-protocols) - [Controllers](https://homenetworks.com.au/guides/smart-home-ecosystems) - [Networks](https://homenetworks.com.au/guides/smart-home-network) - [Blog](https://homenetworks.com.au/smart-home-networks-and-iot-blog) - [Support](https://homenetworks.com.au/contact-us) - About Us [Shop](https://shop.homenetworks.com.au) - Home - Products & Solutions - Networking - [Aruba Instant On](https://homenetworks.com.au/network/hpe-aruba) - [TP-Link Omada](https://homenetworks.com.au/network/tplink-omada) - [HPE Juniper Networks](https://homenetworks.com.au/network/hpe-juniper) - Smart Home Controllers - Home Assistant (HAOS) - openHAB - [NUC Build Configurator](https://homenetworks.com.au/smart-home-hubs) - Cameras & Security - IoT Devices - Guides - [What is a smart home](https://homenetworks.com.au/guides/what-is-a-smart-home) - [The building blocks](https://homenetworks.com.au/guides/smart-home-building-blocks) - [Connectivity](https://homenetworks.com.au/guides/smart-home-protocols) - [Controllers](https://homenetworks.com.au/guides/smart-home-ecosystems) - [Networks](https://homenetworks.com.au/guides/smart-home-network) - [Blog](https://homenetworks.com.au/smart-home-networks-and-iot-blog) - [Support](https://homenetworks.com.au/contact-us) - About Us [Shop](https://shop.homenetworks.com.au) ![](https://homenetworks.com.au/hs-fs/hubfs/wifi-blog-theory-v-reality2.png?width=2172&height=724&name=wifi-blog-theory-v-reality2.png) # Part 4: Wi-Fi Speeds: Theory vs Reality ![Dave Gilmore](https://app.hubspot.com/settings/avatar/0e8ebed7dfc5b869e670685272c7a0d2) Dave Gilmore October 9, 2026 **The short version:** the number on the box is a best case scenario tested under lab conditions that nobody actually gets, so expect a fraction of it in the real world, and don't panic when it happens. Every router box promises a number that looks brilliant on a shelf, sometimes multiple gigabits per second. Take it with a grain of salt. That number assumes perfect signal, zero interference, and every antenna working at maximum capability all at once, a scenario that exists in a lab and pretty much nowhere else. **Your device is deliberately slowing itself down** Remember our host and their guests from a couple of posts back? Every guest is constantly reading the room: how clearly can I hear the host right now, how much noise is in here, how many other people are trying to talk at once. Your Wi-Fi device does the exact same thing, continuously, using something called a modulation and coding scheme, or MCS for short. When the signal is strong and clean, your device speaks quickly and packs more into each sentence. As signal quality drops, because you've wandered further from the host, or a wall got in the way, or the room got noisier, your device automatically slows down and simplifies what it's saying, so the host can still understand it correctly the first time. That's not your Wi-Fi malfunctioning. That's it working exactly as designed. So real world speed depends on far more than the number on the box: signal strength, interference, channel width, how many antennas are involved, how capable your specific device is, and everything sitting between you and the host that we covered a couple of posts ago. As a rough rule of thumb, expect real world speed to land well under the advertised maximum, often by more than half. **Why cables don't have this problem** A major reason Wi-Fi never matches the performance of cables is how permission to talk works. Think of it like, asking for permission vs begging for forgiveness. Over Wi-Fi, every exchange is a four step conversation: - is the air clear to talk?(Listen first) - Yes, go ahead. (Wi-Fi medium is available) - Here's the data. (Transmit signals) - Got it, confirmed. (Acknowledgement - ACK) Every one of those steps takes a moment, and your device has to wait its turn to even start. And if the channel is busy, the device will implement a random amount of time called a back off timer then will listen again. Optionally Wi-Fi networks can use a RTS/CTS mechanism where a device will RTS - Request to Send then receive a CTS - Clear to Send from the Access Point. This can improve Wi-Fi networks efficiency depending what challenges you are facing. Over Ethernet, there's no room full of guests to negotiate with. It's just two steps: here's the data, got it. No asking permission first, because there's nobody else on the line to interrupt. That difference (wireless engineers call it CSMA/CA on the Wi-Fi side, CSMA/CD on the cabled side) is a big part of why a cabled connection will consistently outperform Wi-Fi at the same rated speed. It's not that Wi-Fi is worse technology, it's that it's doing a lot more polite waiting in the background. **Coming up** Once you understand that the number on the box was never the real target, the natural next question is whether extra hardware, extenders, mesh, a second access point, is actually going to help, or just add another voice to the room. That's next: Mesh Wi-Fi Explained (When It Helps – and When It Doesn't!). ## Share this post [mailto:https%3A%2F%2Fhomenetworks.com.au%2Fsmart-home-networks-and-iot-blog%2Fpart-4-wi-fi-speeds-theory-vs-reality](mailto:https%3A%2F%2Fhomenetworks.com.au%2Fsmart-home-networks-and-iot-blog%2Fpart-4-wi-fi-speeds-theory-vs-reality) ## Keep reading ### [![](https://homenetworks.com.au/hs-fs/hubfs/Ecosystem_Part6_rev2.png?width=1536&height=1024&name=Ecosystem_Part6_rev2.png) Smart home ecosystems Home Assistant Ecosystems Part 6: Leaving Google Home (Without Losing a Thing)](https://homenetworks.com.au/smart-home-networks-and-iot-blog/how-to-leave-google-home-for-home-assistant) ### [![](https://homenetworks.com.au/hs-fs/hubfs/Ecosystem_Part7_rev1.png?width=1642&height=958&name=Ecosystem_Part7_rev1.png) Smart home ecosystems Home Assistant Ecosystems Part 7: Leaving Alexa and Ring (and the Zigbee Chore)](https://homenetworks.com.au/smart-home-networks-and-iot-blog/how-to-leave-alexa-and-ring-for-home-assistant) [![SMH&I](https://homenetworks.com.au/hs-fs/hubfs/Logo%20Transparency%20-01-300px.png?width=300&height=127&name=Logo%20Transparency%20-01-300px.png "SMH&I")](https://homenetworks.com.au/) We build networks for Aussie homes who've outgrown their ISP router or basic mesh WiFi. From prosumer WiFi and smart home automation (HAOS, openHAB) to mini PC home servers, we design systems that just work.  Smart Home Networks and IoT Baulkham Hills, NSW, 2153 0417-427-106 sales@homenetworks.com.au --- Privacy Policy · Legal · © 2026. All rights reserved. ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Dave Gilmore", "url" : "https://homenetworks.com.au/smart-home-networks-and-iot-blog/author/dave-gilmore" }, "dateModified" : "2026-10-09T05:21:30.646Z", "datePublished" : "2026-10-09T05:01:05.000Z", "headline" : "Part 4: Wi-Fi Speeds: Theory vs Reality", "image" : [ "https://homenetworks.com.au/hubfs/wifi-blog-theory-v-reality2.png" ], "mainEntityOfPage" : { "@id" : "https://homenetworks.com.au/smart-home-networks-and-iot-blog/part-4-wi-fi-speeds-theory-vs-reality", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://homenetworks.com.au/hubfs/Logo%20Transparency%20-01-300px.png" } } } ```