What is my real WiFi speed?

[rjalex]

Dear friends,
I am posting the screenshot of two conflicting measure of the WiFi speed from my MacBook Pro (15" 2018 10.14.6) and my home WiFi router.
As you can see the Network Utility gives 54 Mbits/s while by Opt-Clicking the WiFi icon on the taskbar I read the speed as 351 Mbps (same unit as before I guess).
Why the difference?
Which is a better approximation of the real speed? Thank you very much.

 

[Weaselboy]

Link Rate and Transfer Speed | Answer | NETGEAR Support

Link Rate and Transfer Speed

kb.netgear.com

You are comparing link speed vs. transfer rate, two different things. Here is an article that explains a bit.

My MBP shows the same thing.

 

[rjalex]

Aw thank you very much. Interesting.
Now that I moved closer to the router I seen an even higher Tx rate of 975Mbps !!! But the other value stays put at a measly 54 ... Wonder if the latter actually changes and under what circumstances.

 

[Weaselboy]

But the other value stays put at a measly 54 ...

I don't think that will ever change. That is what mine is also and the hardware link speed. My Tx Rate is 866Mbps.

 

[rjalex]

Even after reading the interesting article you kindly linked I still think that with our 802.11ac link the network speed could be higher than 54 Mbps ... go figure

 

[Analog Kid]

Even after reading the interesting article you kindly linked I still think that with our 802.11ac link the network speed could be higher than 54 Mbps ... go figure

I’d check if your router is supporting ac. 54Mbps looks to be the 802.11g rate.

If either the wireless router or the wireless client can support only 11a or 11g, the link rate would be a maximum of 54 Mbps, and the actual data transfer speed would be about 22 Mbps.​

I’m not an expert, but I think this can also happen if you have an older device on a newer network because the network can‘t use all of the capabilities of the newer standard while staying backwards compatible. I think this is why you sometimes find routers with two radios at the same frequency— more advanced routers will try to cluster faster devices to one radio and slower ones to the other.

 

[rjalex]

But as you can see from the screenshot in the OP the link is 802.11ac (which seems supported by my router specs and also by my Mac Pro 2018 chipset). Is there something I'm misunderstanding?

Now this is funny. Just tried connecting to the same router with my old but reliable iMac 2009 (with 10.12.6) As expected it connects only with 802.11n at 300Mbps Tx rate but here Network Utility agrees 100% showing Link Speed 300Mbit/s.

Might this be a bug in the Macbook MacOS ?

 

[Weaselboy]

I’d check if your router is supporting ac. 54Mbps looks to be the 802.11g rate.

I don't believe that is what is going on if you look at his screenshots. Mine is similar. He is connected on 5GHz 802.11ac.

If you read the article I linked, what OP is seeing is normal.

 

[Analog Kid]

I don't believe that is what is going on if you look at his screenshots. Mine is similar. He is connected on 5GHz 802.11ac.

If you read the article I linked, what OP is seeing is normal.

I did read (and quote from) your article. The article compares the reported PHY speed with the measured file transfer rate as reported by the file transfer dialog. That isn’t what OP is doing. OP is looking at two different system reports on the network configuration.

Network Utility doesn’t make an effort to measure throughput. And being exactly 54Mbps, which corresponds to the theoretical performance of one particular standard, seems too unlikely to be a coincidence.

Looking at this again, I think Option-clicking the WiFi menu bar item reports the capability of the network you are attached to (it is the specs for rjanet) and Network Utility reports the capability for your local interface (the en0 interface).

When I look at the Network Utility report for my 2013 MBP, the Ethernet adapter interface reports 1Gbit/s, which is almost certainly not what I’m getting through the link, it’s the PHY rate. When I look at my WiFi adapter, it shows 217Mbit/s— but more interestingly both interfaces report a value for “Model:”.

I don’t see a Model reported for the OP‘s interface. I wonder if that can be a sign of a problem with the hardware— or maybe it’s connected through a different adapter?

 

[Analog Kid]

Also note: OP‘s Network Utility report shows many send errors and no received packets. Something here ain’t right... @rjalex, if you’re getting packets you must be getting them through a different interface?

 

[satcomer]

You don’t know the quick way of holding the Option Key While mouse clicking the WI-Fi Finder Menu icon and it will show you your connection type, channel and speed!

 

[Howard2k]

There's something wrong with the network utility.

Both should be showing my connection speed (shown correctly on the right at 878Mb/s).

Throughput is totally different but both of these metrics are showing connection speed, neither show throughput.

I'm running 10.14.6 second iteration of SU (not SU2). Build 18G95.

 

[rjalex]

So let me wrap up the data (the router has both 2,4 and 5 GHz network with same SSID):

HW	WiFi system report	MacOS level	AltWifi Link Tx rate	New.Util link speed	WiFi conn
MacBook Pro 2018	802.11 a/b/g/n/ac	10.14.6	1053 Mbps	54 Mbit/s	Ch 56 ac
MacBook Air early 2015	802.11 a/b/g/n/ac	10.14	867 Mbps	144 Mbit/s	Ch 56 ac
iMac 27 late 2009	802.11 a/b/g/n	10.12.6	300 Mbps	300 Mbit/s	Ch 56 n

 

[rjalex]

Also note: OP‘s Network Utility report shows many send errors and no received packets. Something here ain’t right... @rjalex, if you’re getting packets you must be getting them through a different interface?

Sharp eye
This is very puzzling. I also think it's not related to the speed mismatches we're seeing.
I am writing this through the en0 wifi interface for sure.
Other than that I have four unused Thunderbolt interfaces (en1-en4)
Also have a "strange" en5 interface which looks pretty static:

Dropbox - File Deleted - Simplify your life

www.dropbox.com

 

[Analog Kid]

Sharp eye
This is very puzzling. I also think it's not related to the speed mismatches we're seeing.
I am writing this through the en0 wifi interface for sure.
Other than that I have four unused Thunderbolt interfaces (en1-en4)
Also have a "strange" en5 interface which looks pretty static:

Dropbox - File Deleted - Simplify your life

www.dropbox.com

It looks like that en5 interface is for the T processor that drives the Touchbar-- apparently it exists even if you don't have the Touchbar installed.

I'm kinda stumped. Like @Howard2k, my MP 2013 is showing 11Mbps (which I think is 802.11b speeds) even though my router says I'm attached to the 5GHz network. I could accept it if they gave different results, but on the face of it, the 11Mbps looks wrong. I'm kind of out of my depth at this point.

 

[Weaselboy]

Again... you are comparing the physical link rate to the transmission rate, and that is not the same thing. My 2018 MBP shows the same thing. If you search the forums you will see new iMac Pro owners reporting the same thing. There is nothing wrong with your MBP.

 

[Howard2k]

Again... you are comparing the physical link rate to the transmission rate, and that is not the same thing. My 2018 MBP shows the same thing. If you search the forums you will see new iMac Pro owners reporting the same thing. There is nothing wrong with your MBP.

No that's not correct. Both of these are supposed to be showing the connection speed, not the throughput.

You're correct that throughput and link rate are not the same, but the Network Utility isn't showing the throughput (nor is it supposed to).

Here's a post from two years ago showing the same issue. It's been around for years but somehow hasn't been fixed.

Link speed Mac OS | Ubiquiti Community

I tried the search and it feels a bit embarrassing I can't find the solution to this (probably very cosmetic) issue... The ilnk speed in Mac OS network

community.ui.com

You can get a feel for the throughput using Activity Monitor Data sent/sec and Data received/sec counters, but that's also not very accurate either. In fact it's really very poor. It's at least indicative though, it's based on reality. The Link Speed in Network Utility is not.

 

[Weaselboy]

You're correct that throughput and link rate are not the same, but the Network Utility isn't showing the throughput (nor is it supposed to).

On this we agree. My point is there is nothing wrong with OP's MBP.

 

[flowrider]

There are a number of sites that test and report overall wifi speed. Here's one:

Speedtest by Ookla - The Global Broadband Speed Test

Use Speedtest on all your devices with our free desktop and mobile apps.

speedtest.net

Lou

 

[Howard2k]

There are a number of sites that test and report overall wifi speed. Here's one:

Speedtest by Ookla - The Global Broadband Speed Test

Use Speedtest on all your devices with our free desktop and mobile apps.

speedtest.net

Lou

No, that's the throughput between your device and a node on the Internet.

If your home Internet connection (and every other transient path) between your device and that end node deep in the Internet has more throughput than your local wifi, then that is somewhat relevant, but really that's unlikely. (Perhaps you're running 802.11b or 802.11g, for example ).

I have 1.3Gb/s wifi at home, but my ISP connection is 40Mb/s down and 10Mb/s up, so this test will never show me a relevant view of my wifi speed since the throughput between my device and the node on the Internet is limited by the 40Mb/s of my Internet connection, even though the connection of my wireless devices can be up to 1,300Mb/s. My Internet speed is only a tiny fraction of my wifi speed, and that's the limiting factor. I think that's pretty typical or most of us.

On this we agree. My point is there is nothing wrong with OP's MBP.

Agreed. Apart from software bugs in Network Utility.

 

[Analog Kid]

Again... you are comparing the physical link rate to the transmission rate, and that is not the same thing. My 2018 MBP shows the same thing. If you search the forums you will see new iMac Pro owners reporting the same thing. There is nothing wrong with your MBP.

The OPs question wasn't asking if there was a problem with their MBP. The question was "which of these measurements is a better approximation of the real speed?". I don't think we've had an answer for that other than "neither". The numbers quoted are theoretical, and one of them appears flat out wrong, but the actual throughput depends on many things.

As far as whether anything is wrong with OPs MBP, I'm not sure we have an answer for that either. Network Utility seems to have a history of reporting incorrect link speeds, but I'm not seeing anything that says it has a history of not recognizing the model, incorrectly reporting send errors, or reporting zero receive packets when the network appears to be working otherwise. Could be a harmless bug, could be a problem-- not sure how to judge that based on the information we have.

 

[Howard2k]

The OPs question wasn't asking if there was a problem with their MBP. The question was "which of these measurements is a better approximation of the real speed?". I don't think we've had an answer for that other than "neither". The numbers quoted are theoretical, and one of them appears flat out wrong, but the actual throughput depends on many things.

As far as whether anything is wrong with OPs MBP, I'm not sure we have an answer for that either. Network Utility seems to have a history of reporting incorrect link speeds, but I'm not seeing anything that says it has a history of not recognizing the model, incorrectly reporting send errors, or reporting zero receive packets when the network appears to be working otherwise. Could be a harmless bug, could be a problem-- not sure how to judge that based on the information we have.

I'm not sure I'd use the term "theoretical". They're supposed to be measurements of bandwidth. Optional clicking the wifi icon is correct, using Network Utility is not correct. That's a real thing all the same (bandwidth). It's further protocol complications that ensure that bandwidth and throughput are materially different (in this case (with wifi) especially). Both are real, both are different measurements.

I'm with you though - as you suggested earlier, if there are packets going one way but not the other we may have asymmetrical routing. That's not what I'm seeing at all, even though I do see the link speed silliness. If someone who had the same model as the OP could comment with relevant screen shots that would be a good guide.

 

[rjalex]

Question ... my router supports having some storage attached to it. If I'd put a USB key with some largish file on it and say I time an FTP session between my Macbook and that, how much would the storage/CPU/software stack latencies impact on the link speed? Would the result give a good estimate of the throughput?

 

[Howard2k]

Question ... my router supports having some storage attached to it. If I'd put a USB key with some largish file on it and say I time an FTP session between my Macbook and that, how much would the storage/CPU/software stack latencies impact on the link speed? Would the result give a good estimate of the throughput?

FTP is certainly one of the slower protocols out there for moving files around. Performance of USB sticks tends to vary considerably too. And to make matters worse, some routers do well with USB attached storage, other routers have the feature there as not much more than a novelty and do a poor job. File size makes a difference too - one large file will give materially different results to a stack of smaller files.

You'd also see significant variation if you have other active wifi devices either in your network or in other networks running in the same frequency range. There may be networks with hidden SSIDs too. There may also be interference from USB3 devices, fluorescent lights, microwave ovens, airports etc. There's a massive amount of variability .

Having said that, I can fairly routinely get around 570Mb/s when moving large files around. Sometimes more, sometimes less, it depends whether I move closer to my router or not. Typically my link speed is around 878Mb/s. Sometimes as high as 1.3Gb/s, sometimes it drops down to 585Mb/s or thereabouts, but 878Mb/s is pretty typical. If your throughput is half of your link speed you're doing pretty well. Typically it will be perhaps 1/3 to 1/2.

 

[rjalex]

Totally agree. The router is kind of locked. Can only do Samba or FTP AFAIK.
But even with your very well described caveats maybe I'll just see between the 900 Mbit/s of the link speed and the measly 54 Mbps of the network utility which is closer (and believe I already know that Network Utility is totally useless). Thank you