WiFi speed for 2 M1 mini computers on same network 300 mps are very different

Check which Wi-Fi band you’re connected to. Hold down the Option (⌥) key and click the Wi-Fi icon in the menu bar on the slower Mac. Look at the Channel value. If it’s between 1 and 13, you’re connected to the 2.4 GHz band. If it’s 36 or higher, you’re connected to the 5 GHz band.

Also check the RSSI value. If it’s significantly lower (for example, -70 dBm or worse) than on the other Mac, a weaker Wi-Fi signal could explain the slower speeds.

All good advise from the other contributors so far.

The Wi-Fi strength can suffer from poorly shielded USB devices, USB cables and even the other Mac mini.

Mac mini's are more prone to interference because the wireless antenna is built into the bottom cover.

see > Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support

Ethernet requires Cat 5e or 6 for 1Gbps and Cat 6a higher for 10Gbps.

Location, location, location.

Distance from WiFi base station.

Objects (walls, floors, metal appliances, water sources, etc…) between Mac mini and WiFi base station.

Devices plugged into the Mac mini that may cause WiFi interference (poorly shielded USB devices can cause radio interference).

Do you have any of these files, "cleaning", "optimizing", "speed-up", anti-virus or VPN apps on one Mac and not on the other?

If your WiFi router has the capability (most do), split the 2.4 GHz and 5 GHz bands into two separate networks. Then you connect the devices that need the speeds available in the 5GHz band to that network. That way you can guarantee you are connected to the fastest network. Otherwise, when left to auto, it could take some time for the router to decide which network to connect you to.

Then all the slower devices, connect to the 2,.4 GHz network or connect to it when you need greater distance (2.4GHz signals travel much further than 5GHz).

John Minnich wrote:

Have AVAST for virus check and cleaning cache on both Minis.

Add-on anti-malware is a very good possibility for causing the problem. Remove it per the vendor’s instructions, restart, and test again.

Avast has had other issues. They eventually did get fined for that; for not disclosing the sale of personally-identified data in the fine print.

Post the Wi-Fi data from each, as a starting point:

Control-click on the Wi-Fi icon in the menu bar to get this data.

Above example has the potentially-sensitive info expurgated.

woodmeister50 wrote:

If your WiFi router has the capability (most do), split the 2.4 GHz and 5 GHz bands into two separate networks. Then you connect the devices that need the speeds available in the 5GHz band to that network. That way you can guarantee you are connected to the fastest network. Otherwise, when left to auto, it could take some time for the router to decide which network to connect you to.

Check for band steering capabilities first, as that’s a fairly commonly available feature.

John Minnich wrote:

Den.thed, thanks again. I think you got my issue going in right direction. I raised affected Mac mini 1 1/2 inches off table and RSSI Db reduced 20% getting more open space. John

That is good news, you're welcome.

The other thing that you can do to help the Wi-Fi signal, is stand the Mac mini on it's side with the bottom facing in the direction of the Wi-Fi router.

John Minnich wrote:

What cable??

Usually would be a Cat 5E, Cat 6 or Cat 6A cable.

A Thunderbolt cable (Thunderbolt 3 or later) can also be used for a direct connection.

The use of the Ethernet switch on the local router, or a separate network switch, and Ethernet patch cables (Cat 5E or newer) is common.

I once had the 2 Mac Minis on ethenet LAN but limits to 100 mps.

Ethernet cabling, switches, and other gear can be 10 Megabit Ethernet (MbE), 100 MbE, Gigabit Ethernet (GbE), 2.5 GbE, 5 GbE, 10 GbE, or potentially other speeds. Check the docs with the gear for details.

Wired connections not working? Slower? Older cables can either be faulty, or can have too few wires for use with GbE, too. Or the gear can be older.

Performance-wise, Wi-Fi networking can be slower than Gigabit Ethernet, or can be faster. Or can be much faster.

2.4 GHz, 5 GHz, and 6 GHz are the available Wi-Fi bands, though Mac mini with M1 doesn’t support Wi-Fi 6E networking and the 6 GHz band.

Wi-Fi using 5Ghz and 6 GHz connections can be slow, or can be faster than GbE.

Connections using 2.4 Ghz tends to be slow due to uncoordinated Wi-Fi networks and other interference.

“5G” is a cellular network term, and unrelated to 5 Ghz Wi-Fi, or to Wi-Fi generally.

And is there a WiFi Extender that can use the fast cable for one one computer?

Um, probably, sure, yes, switches and extenders and bridges can all be employed. Might help. Might not. More info about physical positioning, some comparative Wi-Fi details as requested earlier, and maybe also mapping local Wi-Fi activity using an add-on app such as WiFi Explorer (not free, but useful), can all potentially provide info or options for the current configuration.

Please post the Wi-Fi output requested earlier, as a next step.

Wi-Fi by its very nature can be dodgy even when 2 computers are next to one another as the others have hinted. You can experiment with their positions etc. but the only way you can guarantee maximum speeds is via a cable.

As others have pointed out it can depend on too many factors to diagnose here. You also need to be careful because if you're taking the wifi speed from the Mac's reporting then is the max wireless speed to the next link, not necessarily the actual network speed that it will attain.

A better question to ask is whether you need that throughput? A long time ago I was transferring a lot of data from DVDs (downstairs) to my NAS (upstairs) over my LAN. I spent ages tweaking the upstairs router position to increase the speed but in the end I just moved the NAS downstairs and connected Mac and NAS to the router directly with ethernet cables. The NAS sat on the floor for a couple of days until I got the job done then I put it back upstairs cos the network speed for backups and streaming was OK.

John Minnich wrote:

What cable?? I once had the 2 Mac Minis on ethenet LAN but limits to 100 mps.

And is there a WiFi Extender that can use the fast cable for one one computer?

thanks,

Networking is never trivial.

wrong cable (4 wires vs 8 wires; I got caught by this once), bad or wrong Ethernet switch, an Ethernet switch that downgrades all connections to 100mbs if just one of the devices connected is 100mbs (the Ethernet ports on a WiFi router are basically an Ethernet net switch), bad or wrong Ethernet adapter (there are old USB Ethernet adapters that are only 100mbs), and many more networking traps …