There's nothing to fix! Let's not tell him to rent a Mac. His iMac is just fine. He can't get 10Gbps from the 1Gbps Ethernet port on his Thunderbolt 3 dock via his (still unknown speed) internet.
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Custom iMac capping ethernet speeds to 100Mbps on 1gigabit network
- Thread starter dawnrazor
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Well OWC call it a TB4 hub.. .so who am I correct them...
Anyway leaving that to one side, as I mentioned when I run speed test with the ethernet cable connected to the OWC hub I get approx 500mbps up and down... This is the same for all the other computers in the office... When I unplug the ethernet cable from the hub and plug it directly into the iMac... I get a max of 100mbps up and down...
This is the same at my home as it is in the office... The iMac is capping up/down speeds to around 100mbps and I can't figure out why ...
The internet speed is 1gig theoretical... I'm not complaining about the internet speed I'm wondering why its faster through the hub over Thunderbolt then it is direct into the iMac... same cable... nothing else changed....
As I said I made some assumptions and got some stuff as backwards earlier... but now that I hopefully have it straight I'd like to figure out a way of getting get the iMac ethernet port to return 500mbps speeds... which regardless of it being 1g or 10g it whole be able to accomplish...
well I’ve already admitted to getting a bit mixed up… but what you’ve said there is now redundant… my iMac is not ‘just fine’ the ethernet port is capping out at 100mbps… obviously my internet connection is faster than this and I’m trying to establish what is goign on… you are choosing to ignore that things have moved on from my initial post and that I corrected myself and said mea culpa for getting it wrong in my initial assessment of the situation…
thanks for your helps… its been insightful…
First/easy thing out of the way..
Per OWC, this is the OWC TB4 Hub. Yours is the OWC Thunderbolt 3 Dock. They both can work with TB3 and TB4 devices. It's helpful to know/acknowledge the difference as Apple or others help you troubleshoot.
Next, turn off your iMac's Wi-Fi, then run the speed test, still with the Ethernet cable connected. Also, try your speed via https://fast.com
Finally, go into your iMac's System Preferences, Network, Ethernet, Advanced, Hardware, Speed -> see what the drop-down says per the screenshot from @HDFan directly above this post. Leaving the drop-down on Auto is fine.
If all of the above doesn't resolve the issue, then call Apple and have them walk you through restarting your iMac in Safe Mode and resetting the Ethernet network adapter.
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So, fully acknowledging that you feel like you've already ruled out the Ethernet cable as the source of your problem, because it appears to work fine with the dock... try swapping out the cable anyway for a new and/or known-good Cat7 or better cable, just to see what happens.
Sometimes a cable will seem to work fine with one Ethernet device but will flake out with another -- and you have two decidedly different Ethernet devices, one with a 1Gbps port and the other with a 10Gbps port. Maybe that port on your iMac simply has a lower tolerance for flaky (or lower category) cables, even though the other end of the cable is likely still only connected to a switch with 1Gbps ports.
Failing that, I would next try a direct connection to another computer (preferably one with a 10Gbps connection, if another such device is available to you) and run some computer-to-computer file copy tests to see what it looks like when you reduce the complexity. Needless to say, you'll have to make some manual network adjustments to get this to work -- and of course, as BeatCrazy noted, don't forget to turn off WiFi on both computers for the duration of the tests.
Sometimes a cable will seem to work fine with one Ethernet device but will flake out with another -- and you have two decidedly different Ethernet devices, one with a 1Gbps port and the other with a 10Gbps port. Maybe that port on your iMac simply has a lower tolerance for flaky (or lower category) cables, even though the other end of the cable is likely still only connected to a switch with 1Gbps ports.
Failing that, I would next try a direct connection to another computer (preferably one with a 10Gbps connection, if another such device is available to you) and run some computer-to-computer file copy tests to see what it looks like when you reduce the complexity. Needless to say, you'll have to make some manual network adjustments to get this to work -- and of course, as BeatCrazy noted, don't forget to turn off WiFi on both computers for the duration of the tests.
Yeah, I wouldn't go on OOKLA speeds as a definitive measure. The best way to test, I would think, would be to connect your machine to a 10Gb hub, connect another machine with 10Gb to another port on that hub, and transfer files. That action should saturate the connection, assuming you're going high speed SSD to high speed SSD. If you're at 100 Mbps in that configuration, with cat 7 cables, you definitely have a problem. A previous poster noted that you can get about this mac to tell you the speed limit of the card, what does yours say?
At the very least, if it's reporting 1Gbps as its maximum, they should refund you the difference. Seems like 10Gbps ethernet isn't a daily requirement for what you're doing, so maybe just the refund would do the trick.
At the very least, if it's reporting 1Gbps as its maximum, they should refund you the difference. Seems like 10Gbps ethernet isn't a daily requirement for what you're doing, so maybe just the refund would do the trick.
Those are indeed good troubleshooting steps, but it appears unlikely he has a 10Gbps switch/hub, or even another 10Gbps destination device.
Oops, sorry, I didn't see your last paragraph when I posted my response. We basically said the same thing.
no…. I have an OWC TB4 dock not a TB3 as you keep insisting… its this model
OWC 11-Port Thunderbolt Dock for Mac & Thunderbolt PCs
Expand your workstation with the OWC 11-Port Thunderbolt 4 Dock. Connect all your peripherals, displays, & devices with ease. Simplify your setup now!
eshop.macsales.com
I’ll check the other stuff later on today, but pretty sure I’ve done all those resets etc…
You are correct. I was getting thrown off when you were calling it a 'hub', which is different than the OWC dock (has an Ethernet port).no…. I have an OWC TB4 dock not a TB3 as you keep insisting… its this model
OWC 11-Port Thunderbolt Dock for Mac & Thunderbolt PCs
Expand your workstation with the OWC 11-Port Thunderbolt 4 Dock. Connect all your peripherals, displays, & devices with ease. Simplify your setup now!
I’ll check the other stuff later on today, but pretty sure I’ve done all those resets etc…
Before we go any further, can you please look at about this Mac, and tell us if your machine thinks it has a 10g card? If not, this is all pretty pointless.no…. I have an OWC TB4 dock not a TB3 as you keep insisting… its this model
OWC 11-Port Thunderbolt Dock for Mac & Thunderbolt PCs
Expand your workstation with the OWC 11-Port Thunderbolt 4 Dock. Connect all your peripherals, displays, & devices with ease. Simplify your setup now!
I’ll check the other stuff later on today, but pretty sure I’ve done all those resets etc…
He had a problem that he couldn't send it in and have no mac, I was offering a solution to that. Who am I, or you, to say he can't try to resolve this in the way he wants to.
No offense intended towards you. I was merely thinking we should confirm there's an actual problem, before he starts a repair/replacement process.
So far, it doesn't feel like there's even been appropriate trouble-shooting to indicate there's a real problem. For all we know, the speed test he's been observing is his Wi-Fi connection speed
Okay some news…
Confirming that the iMac has shipped with a 10G ethernet card…
Confirming that my internet connection is 1gig max…
Setting the network settings to 10Gbase-T results in an unstable connection that briefly connects and disconnects … which makes sense as its attempting to go faster than the network… so no surprises there…
Changing that setting to 1000base-T has resulted in ~500Mbps up/down same as the OWC TB4 HUB/DOCK thing…
However… it’s done this in the past and for no reason it just drops down to ~100Mbps with no change to any of the settings….
I will keep an eye on it, but for now I’m using the iMac ethernet port at speeds that are acceptable given the network speed and port type…
Apologies for my confusion in my initial diagnosis of the potential problem… in hindsight this was premature…
Confirming that the iMac has shipped with a 10G ethernet card…
Confirming that my internet connection is 1gig max…
Setting the network settings to 10Gbase-T results in an unstable connection that briefly connects and disconnects … which makes sense as its attempting to go faster than the network… so no surprises there…
Changing that setting to 1000base-T has resulted in ~500Mbps up/down same as the OWC TB4 HUB/DOCK thing…
However… it’s done this in the past and for no reason it just drops down to ~100Mbps with no change to any of the settings….
I will keep an eye on it, but for now I’m using the iMac ethernet port at speeds that are acceptable given the network speed and port type…
Apologies for my confusion in my initial diagnosis of the potential problem… in hindsight this was premature…
Yes, you don't want to test your internet connection but your network connection. OOKLA combines both. To test just the network connection speed my preferred way is to use iperf3 between 2 hosts that have 10 GbE connected directly or via a 10 GbE switch.
me@computer ~ % iperf3 -c 10.0.0.123
Connecting to host 10.0.0.123, port 5201
[ 5] local 10.0.0.100 port 63565 connected to 10.0.0.100 port 5201
[ ID] Interval Transfer Bitrate
[ 5] 0.00-1.00 sec 1.09 GBytes 9.33 Gbits/sec
[ 5] 1.00-2.00 sec 1.09 GBytes 9.32 Gbits/sec
[ 5] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec
[ 5] 3.00-4.00 sec 1.09 GBytes 9.40 Gbits/sec
[ 5] 4.00-5.00 sec 1.10 GBytes 9.41 Gbits/sec
[ 5] 5.00-6.00 sec 1.09 GBytes 9.38 Gbits/sec
...
Fair, but when I see people say they’re using OOKLA, I assume it’s the app doing a test out to a server in internet land. Too many variables there to get a reliable number.
Agreed!No offense intended towards you. I was merely thinking we should confirm there's an actual problem, before he starts a repair/replacement process.
So far, it doesn't feel like there's even been appropriate trouble-shooting to indicate there's a real problem. For all we know, the speed test he's been observing is his Wi-Fi connection speed
Have you checked your iMac?
In Catalina this is what you do:
System Preferences - Network - Advanced - Hardware - Speed - and scroll to find 10Gbase-T.
If you find that then you have got what you paid for.
Cheers
The anecdote I'm about to share is short on details and long on time (over a decade out of date), so this is probably just a mildly interesting unhelpful coincidence at best. So anyway, I had a couple mid 2010 27" custom config i7's that did the exact same thing, but only while connected to not-cheap cisco switches. Plug them into a crappy unmanaged switch, they were perfectly happy. I had late 2009 Core whatever's, mid 2010 i5's, and 2011 imacs that were all rock solid and full wire speed, but those i7's would eventually choke no matter what I tried.
Like an idiot I probably burned about 3 days of troubleshooting after I had the work-around, so I can say it was a hardware issue specific to those i7's and cisco gear. Fortunately for both my own sanity and the sanity of those around me I have since learned to accept the occasional mystery and move on.
Well I am glad I found this thread.
I also ordered a 2020 iMac I9 maxed out from MacSales (OWC). I finally figured out that the 10MB Ethernet running on a 1GB backbone net requires a Cat 6a network cable. I have been fighting the 100mb connection for a couple weeks now and this thread would have saved me a bunch of time. I really don't need 10GBs. 1GB is fine but 100mb is really slow. Replaced network cat 5e with cat 6a and all is well.
A side note here is that I have 200ft in attic of cat 6a and had another 200ft cat 6a cable and I got the full 1gb upload and download. I was not aware that 1gb could go 400ft.
M
I also ordered a 2020 iMac I9 maxed out from MacSales (OWC). I finally figured out that the 10MB Ethernet running on a 1GB backbone net requires a Cat 6a network cable. I have been fighting the 100mb connection for a couple weeks now and this thread would have saved me a bunch of time. I really don't need 10GBs. 1GB is fine but 100mb is really slow. Replaced network cat 5e with cat 6a and all is well.
A side note here is that I have 200ft in attic of cat 6a and had another 200ft cat 6a cable and I got the full 1gb upload and download. I was not aware that 1gb could go 400ft.
M
That is pretty strange, I wonder if there’s something wrong with the 10Gb ethernet on the newer iMacs.
Cat5e should be adequate for 1Gb Ethernet to about 300 feet, and while not technically not spec to do it, can even be used for 10Gbps for short runs.