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donawalt

Contributor
Original poster
Sep 10, 2015
1,280
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After upgrading to 15.0 on Monday, the next speed test I did, and all subsequent speed tests, have dropped!

Since June I have been getting 2200-2300 Mbps d/l speeds without fail. After the upgrade, I get 1800-1900. And it does not fluctuate wildly, like you will see in speed test when there is network congestion. I have tried over a dozen servers through Ookla's app, same result.

I have been thinking this is an ISP issue - but working with them, nothing seems to have fixed it so far. It's probably not anything broken, as my modem's power levels, SNR, and logs are extremely clean all the time. I have no splitters, connections are tight. They have re-provisioned the modem twice.

So today I realized the slow speeds started after I upgraded the Mac to Seqouia 15.0.

So I did a test - I assume this is valid - I ran Speed test on my mac and phone at the same time. I got well over 2200! Thats valid, right?

So now I think 15.0 throttles somehow. Or the adapter I am using has a bug or issue. I am using a good Belkin adapter to connect to USB-C on the Mac.

Is anyone else seeing any issues like this in download performance? Or if you are getting 2200+ direct connected to your router (or through a 2.5+ switch), what adapter do you use to connect the Cat 6 cable to the Mac USB-C cable?

I have Time Machine backups of one of the Macs, I am thinking about holding that, installing the most recent Sonoma, and testing again. Then I can restore using my TM backup to 15.0. Will that work? What's the best way to get the latest Sonoma installed on my laptop?

Thanks for help with my questions!
 
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SG-

macrumors regular
Jun 8, 2015
149
88
seems the same here on my MacBook Air M3 with my 2.5Gbit Anker USB-c adapter:

16780444254.png
 

dmccloud

macrumors 68040
Sep 7, 2009
3,124
1,885
Anchorage, AK
After upgrading to 15.0 on Monday, the next speed test I did, and all subsequent speed tests, have dropped!

Since June I have been getting 2200-2300 Mbps d/l speeds without fail. After the upgrade, I get 1800-1900. And it does not fluctuate wildly, like you will see in speed test when there is network congestion. I have tried over a dozen servers through Ookla's app, same result.

I have been thinking this is an ISP issue - but working with them, nothing seems to have fixed it so far. It's probably not anything broken, as my modem's power levels, SNR, and logs are extremely clean all the time. I have no splitters, connections are tight. They have re-provisioned the modem twice.

So today I realized the slow speeds started after I upgraded the Mac to Seqouia 15.0.

So I did a test - I assume this is valid - I ran Speed test on my mac and phone at the same time. I got well over 2200! Thats valid, right?

So now I think 15.0 throttles somehow. Or the adapter I am using has a bug or issue. I am using a good Belkin adapter to connect to USB-C on the Mac.

Is anyone else seeing any issues like this in download performance? Or if you are getting 2200+ direct connected to your router (or through a 2.5+ switch), what adapter do you use to connect the Cat 6 cable to the Mac USB-C cable?

I have Time Machine backups of one of the Macs, I am thinking about holding that, installing the most recent Sonoma, and testing again. Then I can restore using my TM backup to 15.0. Will that work? What's the best way to get the latest Sonoma installed on my laptop?

Thanks for help with my questions!

1. Which model of the Belkin adapter are you using? For some reason, I think there was a thread related to Belkin ethernet adapters at some point in the last year or so.

2. You said you ran the speedtest on your Mac and phone at the same time. What router are you currently using?
 

donawalt

Contributor
Original poster
Sep 10, 2015
1,280
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Yep just proved this is a BUG in 15.0!

@dmccloud - it's the Belkin USB Type C to 2.5 Gb Ethernet Adapter, which always worked fine. My router is an Orbi 970, plenty fast enough (10G and 2.5G ports)

So here is how I proved it - @SG- good to know your adapter is an Anker, so it's not adapter specific - mine is a Belkin USB Type C to 2.5 Gb Ethernet Adapter...

I went back to Sonoma 14.3.1 - and I get 2300 d/l speeds! So it's not my ISP! On Sequoia 15.0 I get 1800-1900.

I'll file a bug...
 

Bigwaff

Contributor
Sep 20, 2013
2,701
1,811
With your ethernet adapter attached, open System Information > Ethernet and locate your adapter. Curious which driver is loaded in Sonoma vs Sequoia.
 

donawalt

Contributor
Original poster
Sep 10, 2015
1,280
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Is this what you are looking for @Bigwaff ? This is from the 15.0 install. I don't have the Sonoma Mac at the moment.

Screenshot 2024-09-20 at 5.33.28 PM.png
 

donawalt

Contributor
Original poster
Sep 10, 2015
1,280
623
By the way i have 2 of the belkin adapters, so I tried on my iPhone 15 Pro Max and iPad Pro, both of which also get the 2200-2300 speeds direct connected - now both at 1800-1900 as well. So it's not MacOS specific.
 

donawalt

Contributor
Original poster
Sep 10, 2015
1,280
623
@SG- @Bigwaff @dmccloud today I got the Sonnettech 10GbE adapter, it gets the right speeds! So MacOS, iOS, iPadOS don't handle the 2.5G adapters at full speed right now. 10GbE adapters, albeit more expensive, are all probably fine.

Screenshot 2024-09-21 at 3.12.21 PM.png
 

Bigwaff

Contributor
Sep 20, 2013
2,701
1,811
The driver is Apple provided. macOS will load the NCM driver for 2.5G adapters. Good intro at this link.
 

donawalt

Contributor
Original poster
Sep 10, 2015
1,280
623
FYI this is a bug supporting full speed with the 2.5G adapters....I just set up a 10GbE adapter from Sonnet, and it gets full 2300+ d/l speeds on the same MacBook Pro.
 

donawalt

Contributor
Original poster
Sep 10, 2015
1,280
623
Not fixed in MacOS 15.0.1.......Belkin 2.5G adapter gets around 1945 Mbps d/l/ max, Sonnet 10G adapter gets 2350 Mbps d/l on my Comcast plan.
 

donawalt

Contributor
Original poster
Sep 10, 2015
1,280
623
You get only 300 Ethernet-direct connected to the router or thru a switch to router?
 

Wolf1701

macrumors regular
Sep 16, 2006
225
228
Same here, two macs m1 and m1pro with sequoia i have lost 300 mbps with dlink 2.5gbps usbc adapters
 
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donawalt

Contributor
Original poster
Sep 10, 2015
1,280
623
I provided feedback too, on Sep 21. I just updated it to include that 18.0.1 has the problem too, and added a link to this thread.
 
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