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chrisgeleven

macrumors 6502
Original poster
Apr 28, 2002
485
71
Just received my Studio Display and plugged in a Belkin USB-C ethernet adapter I bought on Amazon. MacBook Pro M1Pro. I can't get over 400Mbps no matter what I do. I suspect there is a driver issue.

Any ideas on what USB-C ethernet adapter can reach full Gigabit speeds that is plug-in-play (no driver installs)?

I have the old Thunderbolt 2 ethernet adapter into a Thunderbolt 3 adapter and that gets full 1 Gigabit speeds, so nothing wrong with the ethernet cable.
 
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FNH15

macrumors 6502a
Apr 19, 2011
659
663
Just received my Studio Display and plugged in a Belkin USB-C ethernet adapter I bought on Amazon. MacBook Pro M1Pro. I can't get over 100Mbps no matter what I do. I suspect there is a driver issue.

Any ideas on what USB-C ethernet adapter can reach full Gigabit speeds that is plug-in-play (no driver installs)?

I have the old Thunderbolt 2 ethernet adapter into a Thunderbolt 3 adapter and that gets full 1 Gigabit speeds, so nothing wrong with the ethernet cable.

Weird, as I get gigabit speeds with that exact adapter (and I have the same machine as you, too).
What speeds do you get plugged directly into the Mac?
 

klky

macrumors regular
Oct 30, 2015
194
249
I also use the Belkin USB-C gigabit ethernet adaptor purchased from Apple. Connected directly to my M1 Max MBP, I get speeds of 900+Mbps. I tried connecting it to my LG UltraFine 5K and it only manages to hit speeds of around 500+Mbps. I've not installed any drivers. Just plug-and-play.
 

4sallypat

macrumors 68020
Sep 16, 2016
2,444
2,110
So Calif
I didn't think the USB-C ports would work well with Ethernet due to the lower speeds compared to the Display Studio's TB port.

Try connecting the adapter direct to your Macbook.

I use the Belkin USB-C adapter on my work Macbook Pro and it gets almost a full gigabit (our work network is 10GB).
 

FNH15

macrumors 6502a
Apr 19, 2011
659
663
Did you connect yours to the studio display or your MacBook Pro? I was hoping I could connect mine to the display but it doesn't work :(

What is the link speed of the adapter in System Information?

Unfortunately I don’t have a Studio Display (yet) to test...
 

chrisgeleven

macrumors 6502
Original poster
Apr 28, 2002
485
71
Sorry all, been real busy the past few days and haven't had a chance to look at this more.

Test methodolgy: I used speedtest.net with a Comcast server in Boston, MA, which is close to where I live and I'm on Comcast as well.

So I've confirmed with three different ethernet adapters the following when plugged directly into a Macbook Pro 14":
- Thunderbolt 2 ethernet with Thunderbolt 3 adapter: ~920 Mbps
- Belkin USB-C ethernet adapter: ~920 Mbps
- Uni USB-C ethernet adapter with 3 USB-A ports: ~910 Mbps

Things get interesting with the Apple Studio Display:
- Belkin USB-C ethernet adapter: ~425 Mbps
- Uni USB-C ethernet adapter: ~400 Mbps

Why would the Apple Studio Display USB-C ports see much worse performance?
 

DragonPrime120

macrumors member
Apr 21, 2015
84
60
Sorry all, been real busy the past few days and haven't had a chance to look at this more.

Test methodolgy: I used speedtest.net with a Comcast server in Boston, MA, which is close to where I live and I'm on Comcast as well.

So I've confirmed with three different ethernet adapters the following when plugged directly into a Macbook Pro 14":
- Thunderbolt 2 ethernet with Thunderbolt 3 adapter: ~920 Mbps
- Belkin USB-C ethernet adapter: ~920 Mbps
- Uni USB-C ethernet adapter with 3 USB-A ports: ~910 Mbps

Things get interesting with the Apple Studio Display:
- Belkin USB-C ethernet adapter: ~425 Mbps
- Uni USB-C ethernet adapter: ~400 Mbps

Why would the Apple Studio Display USB-C ports see much worse performance?
Just curious, are you using the cable that came with the Studio Display? I’ve noticed some third party thunderbolt cables are only rated for 20Gbs and sometimes that makes the ports on the back default to USB 2 speeds.
 
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chrisgeleven

macrumors 6502
Original poster
Apr 28, 2002
485
71
Just curious, are you using the cable that came with the Studio Display? I’ve noticed some third party thunderbolt cables are only rated for 20Gbs and sometimes that makes the ports on the back default to USB 2 speeds.
Thunderbolt cable that came with the Studio Display.
 

shaown

macrumors regular
Mar 24, 2011
132
35
I would assume you don't have enough bandwidth for display + camera + speakers + mic + 1 GB Ethernet.
 

kkclstuff

macrumors regular
Apr 18, 2015
218
156
NYC
+1^^^ ...and charging the MBP via the SD. Ive wondered about my new setup and using a hub with the MBP + SD. I recall reading here or 9to5 about data bottlenecks with charging from SD to MBP.

you might try charging your MBP from its MagSafe power supply while the hub is used from SD and report back ?
 

southerndoc

Contributor
May 15, 2006
1,564
324
USA
I'm guessing this answers my question if you can use a 2.5G/5G ethernet adapter on the monitor. My wife will just have to settle into plugging in 2 cables into her MBP (power/Thunderbolt to Studio Display, 10G ethernet adapter). She was wanting to plug only one cable up. So I thought I might could find a 2.5/5G USB-C adapter, but this thread doesn't give me much hope of getting >1G performance.
 

chrisgeleven

macrumors 6502
Original poster
Apr 28, 2002
485
71
I'm guessing this answers my question if you can use a 2.5G/5G ethernet adapter on the monitor. My wife will just have to settle into plugging in 2 cables into her MBP (power/Thunderbolt to Studio Display, 10G ethernet adapter). She was wanting to plug only one cable up. So I thought I might could find a 2.5/5G USB-C adapter, but this thread doesn't give me much hope of getting >1G performance.
Well, I have some good news.

As part of this mystery, I ordered several USB-C Ethernet adapters to test:

Belkin 1G model - ~400 Mbps max through Studio Display :(
Uni 1G model with USB-A ports - ~400 Mbps max through Studio Display :(
Anker 2.5G model - Just arrived a hour ago and...drumroll...~936 Mbps max through Studio Display!

For whatever reason, the Anker 2.5G Ethernet adapter works perfectly. I did have to plug it into my MacBook Pro directly and reboot first to get it recognized, but once I did that and plugged it into the Studio Display, I was in business! I don't have a 2.5G network here, so I can't test its true max speed, but it is definitely hitting the limits of my Gigabit (1G) network.

Conclusion, there is no Studio Display USB bandwidth limit that these adapters are hitting. Clearly, some sort of driver issue with the Belkin and Uni 1G ethernet adapters that causes bandwidth issues with the USB hub in the Studio Display. Go with a 2.5G Anker and you should be in business.
 
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embotix

macrumors member
Sep 10, 2016
59
15
For whatever reason, the Anker 2.5G Ethernet adapter works perfectly. I did have to plug it into my MacBook Pro directly and reboot first to get it recognized, but once I did that and plugged it into the Studio Display, I was in business! I don't have a 2.5G network here, so I can't test its true max speed, but it is definitely hitting the limits of my Gigabit (1G) network.
Very interesting! I don't know if I would consider this thread to be "resolved", though - it seems to me that the ASD should support better throughput with a 1gbps adapter. Perhaps we'll see some improvements over time with firmware updates.

But I'm sure as hell am going to go ahead and buy the 2.5 dongle for now anyway! ? Tnx for the tip.
 

chrisgeleven

macrumors 6502
Original poster
Apr 28, 2002
485
71
Very interesting! I don't know if I would consider this thread to be "resolved", though - it seems to me that the ASD should support better throughput with a 1gbps adapter. Perhaps we'll see some improvements over time with firmware updates.

But I'm sure as hell am going to go ahead and buy the 2.5 dongle for now anyway! ? Tnx for the tip.
That's fair! I'll change it to not be resolved, as clearly there is some sort of bug with Realtek-based 1Gbps ethernet adapters and the Apple Studio Display.

And yeah, I needed an ethernet adapter anyways, so a 2.5Gbps one is a bonus in that it should last me awhile until 10Gbps becomes the norm :)
 

thatsthequy

macrumors regular
Aug 25, 2015
126
118
Vancouver, BC
Just got my ASD today, and using this same adapter I max out around 430Mbps-450Mbps. Not sure I can verify the bottleneck is the monitor though, as the other end of the ethernet goes into a wireless eero 6+. If I connect the Belkin adapter directly to my Mac I get the same throughput. My ISP speeds are 500/100, so seems like even if the bottleneck is there, its not that big of a deal for me.


Also, I assume it was you, but this was briefly brought up on today's ATP episode (to be released next week).
 
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Elcuria

macrumors member
Nov 8, 2012
42
24
Howdy.

I think a better test for people is to test speed on your home LAN. There's too many variables introduced when your test goes "outside the wire" so to speak of your home network and tests an endpoint on the commercial internet. There could be latency from n+1 hops, and latency at the endpoint being used for the test.
 
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BeatCrazy

macrumors 68040
Jul 20, 2011
3,553
2,385
Well, I have some good news.

As part of this mystery, I ordered several USB-C Ethernet adapters to test:

Belkin 1G model - ~400 Mbps max through Studio Display :(
Uni 1G model with USB-A ports - ~400 Mbps max through Studio Display :(
Anker 2.5G model - Just arrived a hour ago and...drumroll...~936 Mbps max through Studio Display!

For whatever reason, the Anker 2.5G Ethernet adapter works perfectly. I did have to plug it into my MacBook Pro directly and reboot first to get it recognized, but once I did that and plugged it into the Studio Display, I was in business! I don't have a 2.5G network here, so I can't test its true max speed, but it is definitely hitting the limits of my Gigabit (1G) network.

Conclusion, there is no Studio Display USB bandwidth limit that these adapters are hitting. Clearly, some sort of driver issue with the Belkin and Uni 1G ethernet adapters that causes bandwidth issues with the USB hub in the Studio Display. Go with a 2.5G Anker and you should be in business.

Did you test with Wi-Fi turned off? I ask, because if the Belkin/Uni adapter were simply 'not recognized' (as opposed to limited) via the Studio Display, your test would default to Wi-Fi which could certainly peak at ~400Mbps.
 
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thatsthequy

macrumors regular
Aug 25, 2015
126
118
Vancouver, BC
Howdy.

I think a better test for people is to test speed on your home LAN. There's too many variables introduced when your test goes "outside the wire" so to speak of your home network and tests an endpoint on the commercial internet. There could be latency from n+1 hops, and latency at the endpoint being used for the test.
I agree, although I don't have any spare machines laying around to use as iPerf servers. Will report back if I can at some point test this.
 

mrj412

macrumors regular
May 27, 2009
141
56
I have the same numbers with the Belkin 1Gb USB-C adapter. I ran the test several times each with similar results.
Doing the testing during working hours, so the throughout on the fiber is slightly slower than usual.

Connected directly to my MacBook Pro:
Screen Shot 2022-04-06 at 1.14.09 PM.png


Connected through the Studio Display:
Screen Shot 2022-04-06 at 1.08.07 PM.png
 

thatsthequy

macrumors regular
Aug 25, 2015
126
118
Vancouver, BC
Follow up... that wasn't so hard to test after all.

With the Belkin USB-C adapter out the back of the Studio Display, I could peak at ~525Mbps using iPerf3 (direct ethernet to server device). When Belkin is patched into MacBook Pro directly, consistent 943Mbps.

I have a Plugable brand 2.5Gbit adapter arriving tomorrow, will follow up with test results from that.
 
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kevcube

macrumors regular
Nov 16, 2020
197
212
Conclusion, there is no Studio Display USB bandwidth limit that these adapters are hitting. Clearly, some sort of driver issue with the Belkin and Uni 1G ethernet adapters that causes bandwidth issues with the USB hub in the Studio Display. Go with a 2.5G Anker and you should be in business.
there's no difference in drivers for these hardwares, the usb-ethernet interface is very standard.

I personally don't trust most Belkin products, but love Anker. IDK about Uni.
 

thatsthequy

macrumors regular
Aug 25, 2015
126
118
Vancouver, BC
Seems these 2.5Gbit adapters are the way to go, even if the rest of your networking gear is only 1Gbit. Got this Plugable one and it also does 943Mbit solid when connected via the display.

 
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