Building A Computer Network For Production
I'm only going to talk about a Local Area Network here not connecting to the Internet.
The most important question is how fast do you need things to be. The more computers, users, and devices transferring simultaneously, the more the chance of bottlenecking. If you can wait for things to transfer or the slowdown is temporary and isn't crippling then speed doesn't have to be top priority. You can use built in monitor apps in MacOs or Windows to see how much bandwidth something is taking. Remember that the realistic bandwidth is different than theoretical.
In today's age wireless is important so I will include that in the discussion as a must. Because of varing conditions with interference, wireless is never guaranteed in speed. So I will talk about it's theoretical speed. For wired, it's speed is pretty consistant.
Distinct Functional Roles of the Hardware
Nowadays many modems or routers combine a few other roles in the connectivity process as one device. The thing is if you want the best speeds for each, it's probably best they are split up as separate devices. That would allow you to upgrade each separately as well. There's no such thing as the best all rolled up into one device.
- Wireless Access Point - Handles creating wireless service part going to / from wired allowing clients to connect to it.
- Switch - Handles the wired part so devices and link to each other.
- Router - Is like the traffic manager of the networks linking devices so they can communicate with each other and the internet.
- Bridge - The specific functional type I want to mention here is a Wi-Fi to wired ethernet bridge which adds a device wirelessly to a LAN. This make the connection functionally transparent as if it was wired in.
Wired Bandwidth
For wired, the typical standard of speed to see is 1 gigabit (1000 megabits) per second. 1 byte is 8bits so that translates to 125 Megabytes per second. The next standard up in speed is 10 gigabit which is 1250MB/s. Networking protocol overhead actual eats into the bandwidth a little so useable speed is a little less than that. Since 10gb was a bit cost prohibitive for some, manufacturers over time invented 2.5gb and 5gb. Their compatibility is a little bit less so you'll have to see if your devices support such speeds.
The 125MB/s offered from 1 gigabit ethernet can be maxed out these days. If you're doing a lot of large file transfers, SSDs for certain can saturate that and under certain conditions (large contiguous fils) HDDs can exceed that also. So if you're transfering a lot to/from a NAS from drives, it's worth looking at to see if you'll be challenged. Using the internet will not typically benefit from faster speed here as the internet is usually slower. Only those with 1 or 2 gigabit fiber may see some boost in speed IF doing large transfers and the servers pushing it can handle it.
All in one routers don't usually have built in multi port 10 gigabit switches. Maybe they might have one port which could then connect to a separate switch (which could be faster and/or have more ports).
Wireless Bandwidth
There have been plenty of Wi-Fi standards. Each always added more speed and some new features. You may have heard of some like Wi-Fi 5, 6, 6E, 7. They are the generations of Wi-Fi. That naming convention started with 4 so the previous versions didn't have any. I mentioned 5, 6, 6E, and 7 because they are the most seen in 2025. I myself still use some Wi-Fi 5 (AC) routers because for most practical purposes it's still quite useable.
Via Wikipedia:
| — | 802.11b | 1999 | 1–11 | 2.4 | |
| — | 802.11a | 1999 | 6–54 | 5 | |
| — | 802.11g | 2003 | 2.4 | ||
| Wi-Fi 4 |  | 802.11n | 2009 | 6.5–600 | 2.4, 5 |
| Wi-Fi 5 |  | 802.11ac | 2013 | 6.5–6,933 | 5[a] |
| Wi-Fi 6 |  | 802.11ax | 2021 | 0.4–9,608 | 2.4, 5 |
| Wi-Fi 6E[b] | 2.4, 5, 6 | ||||
| Wi-Fi 7 |  | 802.11be | 2024 | 0.4–23,059 | 2.4, 5, 6 |
| Wi-Fi 8[2][3] | — | 802.11bn | 100,000[4] | 2.4, 5, 6 |
6, 6E, and 7 offer not only more bandwidth but multitasking with multiple users with a tech called MU MIMO (Multi User Multiple In Multiple Out). Both the sender and receiver must support the tech to use it. In not bothered by the lack of this in Wi-Fi 5 or early Wi-Fi 6 implementations as I manually setup multiple bands and channels to manually allocate certain devices to minimize traffic jamming themselves.
The bands are the operating frequency of the Wi-Fi. They are currently 2.4ghz, 5ghz, and 6ghz. It's possible to setup multiple frequencies as long as they don't interfere with each. If the sending and receiving device are on the same Wi-Fi channel, they essentially compete with bandwidth. One scenario I like doing this separation is when there's a lot of phone traffic going to computers e.g. NDI, AirDrop. Another scenario is for live streams. Now ideally it's best to be wired but sometimes if wireless is the only option, giving 1 device their own isolated W-Fi is next ideal thing.
The newer Wi-Fi tech is better in regards to bandwidth management and reception. I get it as those were historically weaker points to be addressed as things progressed but since it's still limited in the sense that the Wi-Fi in the clients limit compatibility and sometimes you don't know what's happening in automatic operating mode. So I prefer this more manual approach.
Doing the Math
So the simultaneous of all transfers shouldn't exceed the functional bandwidth of each port / channel unless you are ok with a slowdown. How long things can take to transfer can be calculated using a calculator online like this,