Slow MacOS gigabit, but fast Windows gigabit. Huh?

[RelativeOptics]

Just posted on Apple Discussion about this exact issue, here's my post:

I haven't been able to get gigabit (1 Gb/s) download speeds on my Macbook Air 2015. I've tried using USB3.0 and Apple's Thunderbolt ethernet adapters, and the maximum I'm getting is 450 Mb/s. Plugging the same ethernet cord and USB3.0 adapter into a windows PC delivers 950 Mb/s speeds. Interestingly, plugging either the USB3.0 or Apple thunderbolt adapter into a second Macbook Air 2015 results in the 450 Mb/s speeds. In both cases, I closed Dropbox and other programs that use the ethernet connection and WiFi was off. It makes no difference.


I'm using https://www.speedtest.net/ to check my speeds.


To me, this is fairly convincing evidence that the issue with speed is specific to Macbook Air 2015. Does anyone have a MacBook Air 2015 that can get 1 Gb/s download speeds? Any troubleshooting advice?

 

[WilliamG]

Just posted on Apple Discussion about this exact issue, here's my post:

I haven't been able to get gigabit (1 Gb/s) download speeds on my Macbook Air 2015. I've tried using USB3.0 and Apple's Thunderbolt ethernet adapters, and the maximum I'm getting is 450 Mb/s. Plugging the same ethernet cord and USB3.0 adapter into a windows PC delivers 950 Mb/s speeds. Interestingly, plugging either the USB3.0 or Apple thunderbolt adapter into a second Macbook Air 2015 results in the 450 Mb/s speeds. In both cases, I closed Dropbox and other programs that use the ethernet connection and WiFi was off. It makes no difference.


I'm using https://www.speedtest.net/ to check my speeds.


To me, this is fairly convincing evidence that the issue with speed is specific to Macbook Air 2015. Does anyone have a MacBook Air 2015 that can get 1 Gb/s download speeds? Any troubleshooting advice?

You're likely not going to get any definitive response. I'm still suffering from this issue on a 2014 5K iMac, and a 2018 Mac mini. No issues in Windows.

 

[DayBowBow]

I too have this issue. I just got century link 1Gb service and get half the download speed on my Hackintosh, 2013 15inch MBP and 2011 13" MBP. Hard wired the tech got 900/900, Sitting right next to him hard wired with my MBP i got 450/900 to the same server. Over AC1300 i get 250/500, and N450 I get 250/250.

I speed tested 70 different servers. Found about 8 that would go above 500 down over ethernet. Found 2 that would hit 850+. It seems like any server on Level 3 or century links system has this issue. Servers from other ISPs seem to do better. For anyone that wants to do some testing I have found QTS servers to have good speed and even down and up speeds. The Fibersphere communications server in portland OR has the best speeds I have found. Wave servers also seem decent.

Here is another thread about the issue that is interesting. https://www.dslreports.com/forum/r3...Great-on-Gig-Fiber-Download-Speed-Not-so-much

I have tried tuning the TCP settings from these links. Didnt seem to help. Maybe someone can do more experimenting with them and find something that works.

http://slaptijack.com/system-administration/mac-os-x-tcp-performance-tuning/
https://rolande.wordpress.com/2014/05/17/performance-tuning-the-network-stack-on-mac-os-x-part-2/
https://fasterdata.es.net/host-tuning/osx/
https://gist.github.com/mthrynn/98e34d4fda5a405b918a6d734ac40977
https://lists.apple.com/archives/darwin-kernel/2012/Apr/msg00042.html

Quick note: If you want to increase kern.ipc.maxsockbuf=16777216 you will first need to change
nvram boot-args="ncl=131072" by logging on in recovery mode then rebooting. Default settings is
nvram boot-args="ncl=32768" All the other settings are reset after a reboot. You can make/edit the sysctl file in etc/sysctl.conf to have them load on boot if you find something that works.

 

[WilliamG]

I too have this issue. I just got century link 1Gb service and get half the download speed on my Hackintosh, 2013 15inch MBP and 2011 13" MBP. Hard wired the tech got 900/900, Sitting right next to him hard wired with my MBP i got 450/900 to the same server. Over AC1300 i get 250/500, and N450 I get 250/250.

I speed tested 70 different servers. Found about 8 that would go above 500 down over ethernet. Found 2 that would hit 850+. It seems like any server on Level 3 or century links system has this issue. Servers from other ISPs seem to do better. For anyone that wants to do some testing I have found QTS servers to have good speed and even down and up speeds. The Fibersphere communications server in portland OR has the best speeds I have found. Wave servers also seem decent.

Here is another thread about the issue that is interesting. https://www.dslreports.com/forum/r3...Great-on-Gig-Fiber-Download-Speed-Not-so-much

I have tried tuning the TCP settings from these links. Didnt seem to help. Maybe someone can do more experimenting with them and find something that works.

http://slaptijack.com/system-administration/mac-os-x-tcp-performance-tuning/
https://rolande.wordpress.com/2014/05/17/performance-tuning-the-network-stack-on-mac-os-x-part-2/
https://fasterdata.es.net/host-tuning/osx/
https://gist.github.com/mthrynn/98e34d4fda5a405b918a6d734ac40977
https://lists.apple.com/archives/darwin-kernel/2012/Apr/msg00042.html

Quick note: If you want to increase kern.ipc.maxsockbuf=16777216 you will first need to change
nvram boot-args="ncl=131072" by logging on in recovery mode then rebooting. Default settings is
nvram boot-args="ncl=32768" All the other settings are reset after a reboot. You can make/edit the sysctl file in etc/sysctl.conf to have them load on boot if you find something that works.

Thanks for chiming in. I’ve yet to solve this on any of my Macs. My Windows machines right next to my Macs continue to have zero issues hitting full throughput.

 

[ZipZap]

I just upgraded to the Xfinity Gigabit:

Using the correct CAT ethernet Cable, I link the Xfinity router to my 472XT QNAP through the 10 GBE port.
I connected the QNAP to my iMac pro using an active 40 gbps TB3 cable.
I configured a software switch on my QNAP so I obtain the internet on my iMac through the QNAP.
I get nearly a gig of speed.

I could achieve the same by just using the right ethernet cable and plugging it directly into the 10 gbe Ethernet on my iMac Pro.

Right ports and right cables a must.

 

[MikeCP]

I'm 90% sure that...MacOS Catalina fixes this.

A little unscientific, but I'm currently dual booting between Catalina and Mojave. Mojave max DL speed is 500 or so. Catalina is 900. Same as Windows.

 

[WilliamG]

I'm 90% sure that...MacOS Catalina fixes this.

A little unscientific, but I'm currently dual booting between Catalina and Mojave. Mojave max DL speed is 500 or so. Catalina is 900. Same as Windows.

Interesting... I may have to try this sooner rather than later.

 

[WilliamG]

I'm 90% sure that...MacOS Catalina fixes this.

A little unscientific, but I'm currently dual booting between Catalina and Mojave. Mojave max DL speed is 500 or so. Catalina is 900. Same as Windows.

Installing it now on an external SSD...

 

[WilliamG]

Can confirm on my end that the public beta available of Catalina does indeed solve this issue on my 2014 5K iMac! Now, the OS as a whole isn't ready for me to switch, but it's nice to have something to look forward to on the final release! Yay!

 

[WilliamG]

Gosh I can't wait for the next MacOS version, where this is fixed.

 

[HoodySZN]

I just wanted to chime in as well. I have a 2018 Mac Mini i5 on the latest Mojave and my internet has never been good on this. We have the fastest Comcast tier and while my room isnt the best for superfast internet all my other iDevices work fine, new iPad Pro, XS Max and my older MacBook from 2 years or so ago have no issue from an internet stand point. I'll add my PS4 Pro as having no problems with the internet. My parents wont let me drill a hold in the floor upstairs to put a router down here

 

[1369281]

Just got Frontier FiOS gigabit Internet. 2016 MacBook Pro using USB-C Ethernet adapter. macOS Catalina installed.

Download is around 400-600 Mbps and upload is mid-900 Mbps.

I’ve been talking to very informative Frontier network engineers via direct message on another forum and they can’t find anything wrong on their side.

I think it’s a Mac issue. I am going to perform speed tests with other hardware and verify, but all signs point to Mac.

@WilliamG, did Catalina resolve your issue?

 

[WilliamG]

Just got Frontier FiOS gigabit Internet. 2016 MacBook Pro using USB-C Ethernet adapter. macOS Catalina installed.

Download is around 400-600 Mbps and upload is mid-900 Mbps.

I’ve been talking to very informative Frontier network engineers via direct message on another forum and they can’t find anything wrong on their side.

I think it’s a Mac issue. I am going to perform speed tests with other hardware and verify, but all signs point to Mac.

@WilliamG, did Catalina resolve your issue?

So far, yes. Both my 2014 iMac and 2018 Mac mini have shown much improved download speeds since upgrading. I tested again before and after upgrading, and both show the same improvement.

 

[HoodySZN]

I've grown frustrated with this. Updating to Catalina didn't fix my Mini's wifi issues. It's still slow and I cant even download the latest OS updates. On top of that the wifi adapter I bought that improved my internet issues stopped working because the drivers are incompatible with the new OS. I put Windows 10 using boot camp and on its own the Mini internet was greatly improved. The wifi adapter has updated drivers for Windows and works even better. I bought a different wifi adapter but support only goes to 10.14 but I'm hoping it works. For now I'm stuck on Windows and its awful.

 

[killerrobot]

Did anyone find a full solution to this problem? I have a 2015 4k iMac - I hadn't run any updates on for a while and was sitting on 10.13 because of networking issues with an older mac on the same network. Finally upgraded to 10.15 last month and my gig internet has dropped significantly. Use to run 900 u/d but now it's anywhere from 400 - 600 with full u still over 900.

Techs have been out, all equipment has been swapped numerous times and their boxes connect at 900 u/d. I've narrowed it down to a Mac os issue (currently on 10.15.3) and would definitely like to find a solution.

 

[WilliamG]

Did anyone find a full solution to this problem? I have a 2015 4k iMac - I hadn't run any updates on for a while and was sitting on 10.13 because of networking issues with an older mac on the same network. Finally upgraded to 10.15 last month and my gig internet has dropped significantly. Use to run 900 u/d but now it's anywhere from 400 - 600 with full u still over 900.

Techs have been out, all equipment has been swapped numerous times and their boxes connect at 900 u/d. I've narrowed it down to a Mac os issue (currently on 10.15.3) and would definitely like to find a solution.

I can't say the speeds on my Mac are quite the same as my Windows PC, but 10.15 did fix it for the "most" part. I see 700Mbit downloads and the usual 900+Mbit upload.

 

[WilliamG]

Did anyone find a full solution to this problem? I have a 2015 4k iMac - I hadn't run any updates on for a while and was sitting on 10.13 because of networking issues with an older mac on the same network. Finally upgraded to 10.15 last month and my gig internet has dropped significantly. Use to run 900 u/d but now it's anywhere from 400 - 600 with full u still over 900.

Techs have been out, all equipment has been swapped numerous times and their boxes connect at 900 u/d. I've narrowed it down to a Mac os issue (currently on 10.15.3) and would definitely like to find a solution.

Updated from 10.15.2 to 10.15.3, and updated the Speedtest app, and I'm getting great speeds.

 

[1369281]

A few random thoughts and tips:

1. My specific issue ended up being my ISP's fiber ONT. The model they used had an issue. (Only worry about this if you have Verizon or Frontier Fios.)

2. Don't use a USB gigabit Ethernet adapter through a hub (especially via monitor or keyboard built-in USB inputs). Always use it directly connected to your Mac.

3. Test your local (LAN) speeds with iperf3 before testing your ISP (WAN) speeds.

4. Use speedtest.net CLI instead of browser plugins. It's much more accurate.

 

[killerrobot]

Updated from 10.15.2 to 10.15.3, and updated the Speedtest app, and I'm getting great speeds.

I did the .3 update and it didn't make any difference. Maybe I'll do a clean install of the OS and see if that helps.

 

[WilliamG]

I did the .3 update and it didn't make any difference. Maybe I'll do a clean install of the OS and see if that helps.

It was likely coincidence. I had a different server to test on when I tested again. The results aren't always consistent from server to server, of course.

 

[darthaddie]

Not exactly your issue but I am facing a similar thing with safari

Safari / Catalina throttling downloads? or just slow

Hi, I was switching to a ethernet connection on my Mac Pro 2019 today and in the process of testing and comparing ping/download rates to my WIFI, I discovered that Safari is somehow 50% slow when downloading files to simple throttles the downloads Here are my specs Mac Pro 2019, 12 core...

forums.macrumors.com

 

[pxf]

I had a similar problem, high latency, single digit (Mbps) download speed, upload speed ~40Mbps. I am sure you tried these things, but this is what I did on Mojave to fix the issue.
System Preferences -> Network, then select wired connection
Changed 'Configure IPv4' from 'manually' (don't know why this was set, not my mac) to 'Using DHCP', then selected the the 'Advanced...' button and selected the 'Renew DHCP Lease', now getting almost a 100x speed improvement.

 

[An-apple-a-day]

On a 2016 MBP 15" (Mojave 10.14.6) connected via Apple-supplied (Belkin) USB-C ethernet adapter, I have no trouble achieving 940Mbps up and down on my gigabit fiber internet service.

Don't ever do speed tests within a browser (at least on Mac) if you're trying to measure the speed of a networking connection > ~500Mbps. You will run into a CPU constraint (multiple cores pegged at 100% utilization) and the browser's networking layer will end up being a bottleneck -- thwarting the very connection throughput that you're trying to measure. Firefox is worse than Safari in this regard.

 

[USB3foriMac]

Funny, I had the same result using Safari:

And then installed Firefox as someone suggested, and surprise, surprise:

Note that the values differ each time I run the test, but they were consistently higher for the download when using Firefox.

 

[moral-hazard]

I fought against this problem forever on my 2012 Mac Mini (i5 // Mojave). It was consistently stuck at 200Mbps down, more or less on the dot (fast.com speed test). Same speed in Chrome/Firefox, faster in Safari (up to 260-280Mbps or so). By contrast my WiFi devices (iPhone 8, Macbook Air 2018) were doing 300-400Mbps. Upgrading to Catalina fixed this for me. Everything else (network settings, MTU, energy efficient ethernet settings, etc) had no effect whatsoever.

HTH!