iMac WiFi

Let's look at those values. One measure of Wi-Fi signal quality is the Signal-to-Noise Ratio (SNR). It is calculated as: SNR = Signal - Noise. From those values, RSSI represents the Signal value in that equation ... so, in your case: SNR = -35 - (-93) = 58. An outstanding SNR!

Next, let's look at the Wi-Fi connection itself between the Mac and Google node. To do that we refer to the Tx Rate, PHY Mode, MCS Index, & NSS (Number of spatial streams) values. Let's start with NSS. Your iMac is capable of connecting to a Wi-Fi network with up to 3 spatial streams. This would require that the wireless access point can also support this number of streams. From the image, you can see that your iMac is only connecting with 2 streams. My guess is that this is your Google node and not your iMac that is limiting this.

Finally, we'll take a look at the MCS Index value of 9. For 2 streams and connected with a 80 MHz-wide channel, the connection (in theory) should have a maximum bandwidth capacity of 866.7 Mbps ... which is basically what you see for the Tx Rate. (If you would have had a 3-stream connection, that would be 1300 Mbps.) Note that these rates are theoretical total bandwidth capacity, not the actual throughput speeds. (Think of bandwidth as lanes on a highway, and throughput as the number of vehicles can can travel on those lanes. The more lanes, the greater the throughput.)

So, unless there is some hardware issue with your Mac's built-in wireless AirPort card, the culprit could be two things:

1. Your Google mesh node is limited to only providing up to 2 spatial streams.
2. There is some form of Wi-Fi interference in the nearby area that is adding noise that is limiting the quality of the signal. Since you are seeing SNR values in excess of 30, that would not be the factor here.

No problem. Just checking. The Asus or ones by Synology, would be great choices. Be sure to check out the store's return policy if you should need to return it.

Regardless of which you choose, getting a signal with enough bandwidth at all locations in your home will be the goal. What will challenge that would be any form of Wi-Fi interference. Primarily due to the building construction materials used in your home. Most newer wireless routers operate on both the 2.4 & 5 GHz bands. The higher band, which also offers the better bandwidth, does come with one significant drawback. That is, most of that bandwidth can only be obtained in either the same room or adjacent rooms from the router. So, for example, getting that 5 GHz signal to that second floor may not be possible. Just want you to be aware. This shouldn't be an issue for the lower band.

Wi-Fi is a two-way communication. Just increasing the capability of the wireless router may not be "enough." The wireless client upstairs may be able to "hear" the router, but the router may not be able to "hear" the client as there isn't much you can do to increase the radio power of your Mac's internal wireless card. This is supposedly where the new "mesh" wireless systems were supposed to excel at. Some work better than others. As you now know, Google's system is not working for your situation. I understand that the Linksys Velop system may be worth considering if the single wireless router, you are currently considering, doesn't pan out. FWIW, I overcame this issue by contracting an electrician/network specialist to install Ethernet in my older home. As such, I have zero issues with my Wi-Fi, and can easily stream 4K content to multiple devices throughout my home.

You may find the following references helpful:

• Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support
• Router Ranker - SmallNetBuilder
• The 9 Best Long-Range Routers of 2021 - Lifewire

With Opt key pressed, click on the WiFi icon, snapshot and post here please.

I haven’t seen better! Most likely the router is to blame meaning it’s reaching its limits. I would swap it out for Asus/Netgear/Linksys. Or live with it as the difference is trivial. All the best.

Check the Tx Rate on your screenshot. Looks like 866 Mbps, so you know your Mac can handle a connection up to that speed.

How are you checking speeds?

For overall bandwidth performance, a home wireless network that utilizes an Ethernet backbone, would be the preferable method ... when possible. So the first question to ask you is: Is your home currently wired for Ethernet ... and if not, would it even be a consideration? Depending on your response, I can try to steer you in the proper direction.

Wi-Fi connections will rarely (if ever) top the speed of a direct ethernet cable connection for a number of reasons.

I suspect your 500mbps speed is about the best you're going to get.

That’s not true. A good WiFi AC connection can easily sustain speeds in excess of 1G and under the right conditions, reach 1.3G.

Okay then. I stand corrected. 👍🏽

😉