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gsmornot

macrumors 68040
Original poster
Sep 29, 2014
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Throwing this out to see if there are any ideas. I recently had gigabit internet installed at the house. Testing, my 2011 Mac mini will only reach 136Mbps down but will get 850Mbps up. (over WiFi it will do 136Mbps down and 300Mbps up) Sorry for this next part... my Windows machine (work) will hit 950Mbps in each direction using the same exact cable. I remove the cable from my MAC and plug it into my WIN7 machine. My MacBook Pro, same issue only worse. It will top out at 90Mbps down and 600Mbps up.

All of this is ethernet, CAT6, direct to the provided gateway. I only have two MAC's to test with, one on Sierra and one on High Sierra. The cable used is only 12" long, I wanted to give the machines every chance I could.

I will go ahead and say it before anyone else, I know 136Mbps is plenty but if it could keep up with my WIN machine it would be better. Wonder if age is a factor. I should mention I use an SSD and have 16GB of RAM installed.
 
The first thing I'd try is to see how fast the Macs can communicate with each other, using the router (meaning via the switch built into your router). Nevermind the internet. You'd want to make sure that each Mac transfers to another Mac as fast as it receives from another Mac.

Then you'd know that the Mac ethernet interfaces are properly configured and working as they should.

I use an app called Speedy Net for testing. I'm sure there are others.
 
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The first thing I'd try is to see how fast the Macs can communicate with each other, using the router (meaning via the switch built into your router). Nevermind the internet. You'd want to make sure that each Mac transfers to another Mac as fast as it receives from another Mac.

Then you'd know that the Mac ethernet interfaces are properly configured and working as they should.

I use an app called Speedy Net for testing. I'm sure there are others.
Good suggestion.
 
Network/System Admin here. Your Macs and your switch/router might not be autonegotiating their network connection speed correctly. There are a variety of Ethernet port speeds, and when you connect two devices together, they should auto negotiate the highest common speed. However, this can sometimes fail (hardware vendors not following the standards properly) and leave your machines in a weird state.

You can easily force a particular speed for your network port in macOS. Go to: System Preferences -> Network -> Ethernet -> Advanced -> Hardware, and try setting "Configure" to Manual. Then make sure speed is set to 1000baseT and Duplex is full-duplex, flow-control. Then click OK to save the changes and retry the speed test.

If that doesn't do the trick, try setting it to "full-duplex" only and see if that makes a difference. To revert, just set the "Configure" setting back to Automatic.
 
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The first thing I'd try is to see how fast the Macs can communicate with each other, using the router (meaning via the switch built into your router). Nevermind the internet. You'd want to make sure that each Mac transfers to another Mac as fast as it receives from another Mac.

Then you'd know that the Mac ethernet interfaces are properly configured and working as they should.

I use an app called Speedy Net for testing. I'm sure there are others.
Using Speedy Net, both connected to the same switch I get 890 and at times a bit higher. MackBook on the provided gateway I still see 860+. MacBook on the farthest point in the house I am getting about 790, still very good. I wonder if its Safari. I see another post below with instructions to hardcode. I will try that for fun and see what it does.
[doublepost=1498011787][/doublepost]
Network/System Admin here. Your Macs and your switch/router might not be autonegotiating their network connection speed correctly. There are a variety of Ethernet port speeds, and when you connect two devices together, they should auto negotiate the highest common speed. However, this can sometimes fail (hardware vendors not following the standards properly) and leave your machines in a weird state.

You can easily force a particular speed for your network port in macOS. Go to: System Preferences -> Network -> Ethernet -> Advanced -> Hardware, and try setting "Configure" to Manual. Then make sure speed is set to 1000baseT and Duplex is full-duplex, flow-control. Then click OK to save the changes and retry the speed test.

If that doesn't do the trick, try setting it to "full-duplex" only and see if that makes a difference. To revert, just set the "Configure" setting back to Automatic.
Tried the hard code options with the same result. 136-145 down and about 850 up.
[doublepost=1498012120][/doublepost]Installed Firefox, I get 890+ each direction on SpeedTest.net . Safari I get 136 down and 890+ up. Interesting.
I am seeing this issue with 10.12 and 10.13. Wonder why.
 
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Could it be a Safari add-in/plug-in/extension?
Thought about that but its the same without any extensions. I turned the only one I use off via develop menu.

Interesting though, I can use Safari Technology Preview with dslreports and it shows full speed. Safari won't even run the test. I think its simply something with my Safari or with the one extension I use for ad's. I can't think of anything else.
 
Beta 2 and it works fine now. Well, Speedtest.net looks the same but other speed tests work fine.
 
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