iMac Pro iMac Pro WiFi issue?

[kid2010]

Do anyone else here see their iMac Pro have poor Tx rate with WiFi connection? For some reason my iMac Pro with UniFi UAP‑AC‑HD is experiencing extremely slow Tx rate... My old iMac at the same location can get 1300Mbps while iMac Pro can negotiate to a rate between 6Mbps and 130Mbps...

You can check the detail information about WiFi connection by pressing option and click the WiFi icon.

 

[mcaswell]

I made the same observation a few days ago and posted about it here... it was pointed out that this was merely an error in how the Tx rate was being displayed. Though I initially thought I was also having a very slow network connection that matched this reported speed, this was just a casual observation that a real test subsequently proved false... actual Wi-Fi speed is normal.

 

[bplein]

Per what mcaswell said, this is a bug in the display only. My iMac pro shows 24mbit connection yet I can pull down hundreds of Mbit via speedtest.net.

 

[kid2010]

Huh interesting. For me it's actually this slow. First one was captured over Ethernet connection and second one was over WiFi. On my old iMac, I can get around the same speed (60MB/s) for copying file via SMB on a local network NAS over WiFi at this same location.

What access points are you guys using?

 

[sputnikBA]

Has anyone filed a radar?

 

[dee2thee]

I've actually registered just to chime in on this topic. Same observation here, base model of iMac Pro. Initially I've assumed it's my AirPort Extreme but then I've tested this with another AirPort Extreme as well as when connected to Personal Hotspot on the iPhone. Same problem, always shows 24 Mbps - for comparison MacBook Pro side by side shows correct (much higher) values...

One interesting observation though: when I've connected to a network drive and started copying 20GB file to my desktop, Tx Rate instantly jumped to 1300 Mbps and stayed in 1000-1300 range for the entire process and then went back to 24 Mbps again. Did a similar test with Speedtest.net and again Tx Rate jumped to 1000+ and the actual measured download speed was ~500 Mbps which is as it should be for my bandwidth.

So to me it seems either like some display bug or the wifi module going into some kind of low power / sleep mode when not doing anything network intensive.

 

[phobos]

I do have Wifi issues as well. It looks like the wifi works in bursts. So it does a big burst of data then pauses for several seconds and then it will either time out or continue working.
Couldn't even run Geekbench because at the end when having to upload the benchmarks it was timing out.
At the moment I'm wired in through ethernet otherwise it's just an exercise in frustration

 

[bplein]

What access points are you guys using?

I have UBNT AP-AC-Pro, AP-AC-HD and AP-IW, this test was with the AP-IW which is closest to my iMac (I don't use it however, I have 10gbit wired, only disconnected it for this test)
[doublepost=1515190213][/doublepost]

So to me it seems either like some display bug or the wifi module going into some kind of low power / sleep mode when not doing anything network intensive.

Sounds like it!

 

[kid2010]

I have UBNT AP-AC-Pro, AP-AC-HD and AP-IW, this test was with the AP-IW which is closest to my iMac (I don't use it however, I have 10gbit wired, only disconnected it for this test)
[doublepost=1515190213][/doublepost] Sounds like it!

Mind to share which 10G switch you are using?

 

[bplein]

Mind to share which 10G switch you are using?

UBNT XG.

I had all 4 copper ports as 1GbE uplinks prior, so I unbound 1 of that LACP group and made it normal. My iMac Pro would NOT connect. This is a known issue with the UBNT XG, the copper ports don't have great 10GbE compatibility.

So, having been aware of some of the variations of these issues, I unbound a second port. so ports 13-14 were LACP uplink, 15 empty, and 16 was for the iMac Pro. After a few minutes it connected, but when it woke from sleep it wouldn't connect.

I've always felt that the broadcomm chip used in these was sensitive to adjacent ports, so I then unbound all of them from LACP, and recreated a 2-port LACP on the upper two ()15-16) and then put my iMac on port 13. This works and is stable. I might try adding port 14 to the LACP but no need for now.

I have 2 servers running ESXi with dual-10GbE on the switch, my iMac Pro, and then uplinks to 1GbE switching.

 

[mba0823]

Just wanted to chime in on this as well. I'm not so sure this is an issue with the display only. Downloading a 13 GB file took over 15 hours on the iMac Pro, which took around 10 minutes on a 2012 Macbook Pro (802.11n) sitting right next to the iMac Pro. Wifi info shows the exact same issue as others have noticed. Constantly bouncing between 24 Mbps and 1300 Mbps (sometimes somewhere in between). Network utility shows a link speed of 54 Mbps, and also does not show a Model name or number, which is odd because it should say something like "Wireless Network Adapter (802.11 a/b/g/n/ac)." I'm hoping Apple is aware of this issue and it's as simple as a software update and not a hardware issue.

 

[dr_theopolis]

Same observations here with my iMac Pro. I first found this out when I kept my old iMac (late 2010) side by side with my iMac Pro for migration purposes. I use Slack voice calls often and noticed that performance was choppy and laggy on my iMac Pro. My old iMac a couple of feet away continued to make perfect voice calls. This led me here after I saw the iMac Pro was showing poor and intermittent wifi performance using the Ookla SpeedTest app.

The iMac is connecting to my Netgear C6300 with an unwavering 300 Mbps (802.11n) while my iMac Pro is mostly at 24 Mbps (802.11ac) with sporadic jumps to 1.3 Gbps. The wifi cable modem is about 8 feet away and I'm on clear channels with no obstructions. The Apple Wireless Diagnostic tool performance graph confirms this behavior. I also noticed in addition to brief, random jumps to 1.3 Gbps, when running the speed test it seems to lock to 1.3 until the test is complete followed by a drop back to 24 Mbps. I've tried everything I can find online so far, some of which help my Slack calls for a while but seems to steadily degrade over time. Pretty frustrating.

FWIW, below are idle performance graphs between my iMac and iMac Pro...

 

[sputnikBA]

Has anyone filed a radar?

anyone?

 

[Mackie111]

I just spent some fairly frustrating time on the phone with Apple Support. They appear "not to be aware of this issue" or at least not willing to confirm or deny it. It would be really helpful if more people can talk to them and report this problem please.

 

[bnumerick]

Just wanted to chime in on this as well. I'm not so sure this is an issue with the display only. Downloading a 13 GB file took over 15 hours on the iMac Pro, which took around 10 minutes on a 2012 Macbook Pro (802.11n) sitting right next to the iMac Pro. Wifi info shows the exact same issue as others have noticed. Constantly bouncing between 24 Mbps and 1300 Mbps (sometimes somewhere in between). Network utility shows a link speed of 54 Mbps, and also does not show a Model name or number, which is odd because it should say something like "Wireless Network Adapter (802.11 a/b/g/n/ac)." I'm hoping Apple is aware of this issue and it's as simple as a software update and not a hardware issue.

I reported the Network Utility bug to Apple before 10.3.4 came out. It is pretty frustrating to have to disconnect/reconnect to WiFi all the time while I'm working.

 

[iupdateos]

Having nearly identical issues on my base iMac Pro as well--everything takes much longer to download than on any other Mac connected to the same network. My connection also drops sporadically but fixes instantly once I disconnect and reconnect from wifi...

 

[spacedesign911]

Same issue as some posters with my new iMac Pro, my wifi speed capped out at 24mbps consistently whilst my MacBook Pro and iPhone X on same wifi network touched 360mbps with all three devices sitting side by side on desk 8m away from wifi router, here is my succesfull fix:

Turn off all internet connected apps, and then turn off wifi.

Click on empty area of desktop and click command + option + shift + g together and then paste

/Library/Preferences/SystemConfiguration/

Find and select the following files that are located within the now open SystemConfiguration folder:

com.apple.airport.preferences.plist
com.apple.network.eapolclient.configuration.plist
com.apple.wifi.message-tracer.plist
NetworkInterfaces.plist
preferences.plist

Drag to waste and empty

Reboot, and if necessary, turn on wifi, join network, don't worry if it automagically finds your previous wifi from your existing iCloud synced keychain list of wifi connections.

Wifi speed should be full throttle now.

 

[iMacDragon]

Wifi speed should be full throttle now.

.. just discovered this advice, tried it on my macbook, and.. well, much to my surprise, completely revitalised what I thought was a barely working wifi network. went from struggling to maintain any speed and dropping to nothing to seeming solid full expected AC speeds.

 

[iupdateos]

Turns out my issue was not being caused by the iMac Pro...it was my Eero router. As soon as I switched routers (to Netgear), the dropping issue disappeared and hasn't come back since. Hopefully this helps!

 

[HumpYourWayUp]

Wifi speed should be full throttle now.

Now my iMac Pro Wifi works perfect! Thanks for the tip!