Macbook Air m1 does not reach 1200 mbps

Francesco573 wrote:

Thanks for your answer.

With my current modem I have a 2.5 Gbps subscription, I actually reach about 800 Mbps down and up on Speedtest (Ookla) while sitting right next to the modem.

When I tested other 1 Gbps fiber connections, my MacBook Air M1 was able to reach also 930 Mbps.

So I find it odd that with a faster 2.5 Gbps fiber service that I am actually paying for, I can’t even get close to 1000 Mbps, even under ideal conditions (literally next to the router).

It seems that you are assuming that because your router is capable of 2.5Gbps, that is what you should be getting.

But that does not depend on your router alone.

When you do a speed test, you are connecting to some server somewhere on the internet.

The connection speed will be limited by the slowest item between you and the server.

Metaphors are always imperfect, but:

It's a bit like you have a car (your router) capable of 120Km/h on the highway but if you go through a local road you can't go as fast. It's not the car that is the limitation, it's the road (the many interconnects between you and the server).

It is easier to achieve the stated speed on a slower router, because probably between the router and the server every connection will be able to sustain that speed; but it suffices that one "leg" in your data's journey to be slower for the overall speed to be slower.

As an after thought

Things that could effect through-puts for wifi connections and thusly overhead to the connection

1 - Third Party 2 Way Firewalls 

like Lulu and Little Snitch 

2 - Commercial VPNs 

They may not be what one believes they are doing for the computer and what they actually are doing behind the scenes They may also reduce you Internet Speeds by upwards of 30% 

https://gist.github.com/joepie91/5a9909939e6ce7d09e29

VPN: What you need to know - Apple Community

Francesco573 wrote:

Hi everyone, I have a 2.5 Gbps modem, but I can’t figure out why my MacBook Air M1 can’t reach the maximum speed (1200 Mbps). It’s stuck at around 866 Mbps or a bit lower. I’m already connected to the 5 GHz wifi band, 802.11ax MCS 11, channel 48, 80 MHz, with a tx rate of 1200.

Thanks in advance for your help.

The transfer speeds are limited by the slowest item in the chaing.

There is your connection to the router, the router connection to the internet, and the connection to whichever sites you are accessing. If you are using a high speed internet connection to download a file from a slow server, your download speed will be limited by the server, for example. It is a bit like using a Ferrari in a one way narrow lane, you cannot reach its full speed because the topography of the terrain, and the road, are the limiting factors.

I am using a six-antennae Synology RT6600AX router (Wi-Fi 6) that is about 20 feet in another room with dry wall separation. The firmware is current. It is broadcasting 802.11ax and the recipient is my M4 Mac Mini Pro. The mini is on its side, principally for better access to the power button.

For the same SSID, and Wi-Fi channel 140, I have seen speeds fluctuate between 94 Mbps and 1300 Mbps at 5Ghz @80Hz, and occasionally, 160Hz. I seem to have no control over this behavior with the current configuration. I cannot relocate the router due to the confluence of household network cabling at its location and in this corner of the house, I have no Ethernet cabling to the mini. My cable feed is usually consistent at about 350 - 400 Mbps down.

If I reconfigure my Netgear Nighthawk M6 (MR6550) Mobile Router to transmit Wi-Fi 6E and use its dedicated SSID, the mini will show connections at 6Ghz, 160Hz with Tx varying from 1200 to 2700 Mbps. This is through a T-Mobile 5G UC cellular data connection at 2-3 signal bars. This device uses the Qualcomm X65 radio, same as in the iPhone 16 Pro Max. The distance between the Netgear and mini is about 1 m.

So, two different network devices, ranges, and network service providers, sending Wi-Fi signal to the mini with variable Tx rates. That suggests to me that the Wi-Fi radio in the Mac is the source of the signal reception fluctuation and related hair loss.

Co-incidentally, the above Wi-Fi fluctuation with my Synology router also is observed on my 2020 MacBook Pro M1 Pro still running Sequoia v15.7. The M4 Mac Mini didn't behave differently when it was running this version of macOS or the subsequent Tahoe 26.0.1.

Francesco573 wrote:

Hi everyone, I have a 2.5 Gbps modem, but I can’t figure out why my MacBook Air M1 can’t reach the maximum speed (1200 Mbps). It’s stuck at around 866 Mbps or a bit lower. I’m already connected to the 5 GHz wifi band, 802.11ax MCS 11, channel 48, 80 MHz, with a tx rate of 1200.

Thanks in advance for your help.

To further illustrate what my colleagues is taking about 

I Subscribe to a Fibre Optic service from my ISP,  which does offer up to 10 GB up / download speeds 

Though, I pay for 500 GB up / download speeds 

To Test this, I can log into the Web Interface of the ISP Modem and run a Speed Test from the ISP Server to Modem 

Sure enough, I do get 500+ MB up / download speed 

Doing a similar Test to say SpeedTest dot net

Sure enough, I do get what I have paid for 

Using a M4 Desktop with macOS 26.0.1 Tahoe via Wifi 6E which is currently equal to an Ethernet cable connection 

Francesco573 wrote:

Thanks for your answer.

With my current modem I have a 2.5 Gbps subscription, I actually reach about 800 Mbps down and up on Speedtest (Ookla) while sitting right next to the modem.

When I tested other 1 Gbps fiber connections, my MacBook Air M1 was able to reach also 930 Mbps.

So I find it odd that with a faster 2.5 Gbps fiber service that I am actually paying for, I can’t even get close to 1000 Mbps, even under ideal conditions (literally next to the router).

You certainly have done some good testing 🤞 and deserve acknowledgement for that

Networking issues are not a strong suit of mine

Though as mentioned earlier Paid for 500 MB Up / Download speeds here

The Tx rate indicates a Max of 2.161 Mbps over a 6E wifi connection, will only perform as per the Speed Test

Here, I do ask my colleague ( if they choose to do so (🤞)

There are overheads in Network Connections that will effect the actual speeds attained

You are welcome

Good luck sorting this issue out