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airlied

macrumors 6502
Original poster
Jul 8, 2011
382
59
This is a QacQoc GN28A USB type-C Hub adapter, and it's amazing.

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I got this dongle last year alone with my 2017 MacBook pro 13'. Everyone is gonna get a dongle right? I was happy with the design of the dongle, but at very beginning I was so disappointed with the performance.

It takes up two USB-C ports, providing two back, with two additional USB-A and two SD card readers. I know only one of the type-C ports support power delivery, but what I didn't know is, the same port also is the only one that supports video output. The other USB-C next to it is just a regular 5 GB/s USB 3.0 port, neither support power delivery nor video output.

Because USB type-C was a new thing to me, I thought type-c = USB3 = thunderbolt 3. At that time I didn't know type-c refers just the shape of the connector, it could be Thunderbolt 3, USB 3.1 gen2, 3.0, 2.0 or even just power cord only.

My 4k monitor doesn't provide power to MacBook so if I connect my monitor to the dongle, I have to connect the AC power to the other side of the mac. It against the purpose of buying this, because at least I can plug in video and charging cable at the same side without dongle, but I can't with this.

So I almost forgot I even have this dongle, until yesterday.

My new 2018 MacBook pro works fine with Blackmagic eGPU. The eGPU can charge my mac and doing GPU stuff with one type-c cable, in addition it provides 4 USB-A 3.1 ports. I have a USB-A SD card reader so when I need to read SD card I plugged it in the back of the eGPU, it's inconvenient but not unacceptable. However, I also want to use my Logitech mouse. The mouse has Bluetooth mode but in this mode it's very laggy. It works better with a receiver, but if I plug the receiver on the back of eGPU, it can't pick up the signal from the mouse, the cursor won't move at all.

So I took out the long-time not being used dongle to make Logitech receiver facing towards my mouse. But what about the eGPU? I don't want to plug it to the other side of the laptop since it is so close to the wall. Why not give dongle a try? I think.

And wow! It works!

I'm so amazed since I didn't expect it to be working at all. I went to system configrations.app to check the bandwidth, it did show up to 40Gb/s. Then I ran geekbench 4 Metal test to see if the eGPU could deliver the same performance through the dongle. It gave me 119977, the highest score I have ever had...Then I went to see power information, it did say 85w.
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But I still couldn't believe the dongle supports thunderbolt 3 up to 40Gb/s. It is a 2016 product, with price only is half of some Belkin equivalent (even some fancy Belkin or Satechi dongles don't give you full 40Gb/s bandwidth).

And perhaps QacQoc is a really poorly advertised dongle manufacturer. The manual came with the dongle is so confusing, with nowhere mentioned if it support thunderbolt 3. The official website also didn't say anything about it, it didn't mention if it do support 85w charging. The company really need some good marketing and promo people.
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So I sent them a email asking the specs, they replied with positive answer: yes it's a TB 3 ports with 40Gb/s speed and yes it support up to 87w charging. But the other type-c is just a regular USB 3.0, which I could totally understand, because it occupies just two USB port to provide four USB ports in addition to two SD reader.

I didn't expect that a dongle I bought almost 2 years ago could solve almost all the problems I had. I'm so happy with this dongle. And I think I will keep buying QacQoc and not giving premium to some brand like Belkin.
 
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I guess one of the usb-c ports is just a 1:1 extension of the Mac port, while the other is for the USB hub. Saying that this is a TB3 hub/dongle is misleading, it is essentially TB3 extension cord 1 inch long. And keep in mind, whatever you connect to the dongle will share TB3 bandwidth with eGPU.
 
This is a QacQoc GN28A USB type-C Hub adapter, and it's amazing.

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hi
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I guess one of the usb-c ports is just a 1:1 extension of the Mac port, while the other is for the USB hub. Saying that this is a TB3 hub/dongle is misleading, it is essentially TB3 extension cord 1 inch long. And keep in mind, whatever you connect to the dongle will share TB3 bandwidth with eGPU.

Hi thanks for your reply. I understand your point. Indeed one of the port is just a extension of the mac port. But I dont understand why you said 'whatever you connect to the dongle will share TB3 bandwidth with eGPU'. The dongle itself takes two ports on mac right? If one is an extension, does that mean the other one type-c, alone with two type-A and two SD reader share the other port's bandwidth? So whatever I connect to the dongle would go through the second port, not the eGPU port right? Pleas correct me if I'm wrong.
 
I can't see anything amazing about it. As poster above me says, the high speed you observe is because of a passthrough port. This oversized device blocks the entire side the laptop and trades a full TB3 port for some limited connectivity, essentially being essentially just a card reader + lower-end USB 3.0 ports. With many other dongles you at least get charging + video output as well.
 
But I dont understand why you said 'whatever you connect to the dongle will share TB3 bandwidth with eGPU'. The dongle itself takes two ports on mac right? If one is an extension, does that mean the other one type-c, alone with two type-A and two SD reader share the other port's bandwidth? So whatever I connect to the dongle would go through the second port, not the eGPU port right?
Each side is powered by a separate TB3 controller, one for two ports, so both ports on the same side share the same bandwidth. If you want to be sure your eGPU has always full 40Gbps you need to connect the dongle to the other side.
 
Each side is powered by a separate TB3 controller, one for two ports, so both ports on the same side share the same bandwidth. If you want to be sure your eGPU has always full 40Gbps you need to connect the dongle to the other side.

So you mean two tb3 share 40Gbps bandwidth? If one reaches maximum speed the other drops to zero? If I connect the egpu directly to one of the ports, then whatever I connect to the next port on the same side effects egpu too? Please enlighten me, I do need to know this.
 
I don't really know how to explain it in simpler terms. There are two (2) TB3 controllers in your Mac, not 4. Each controller can do full 40Gbps and has 2 USB-C type connectors. As such both USB-C type ports on each side share the same bandwidth. How the resource allocation priority works in this case I don't know, but most likely it will reduce the eGPU to 30Gbps when full 10GBps are utilized by USB ports on the dongle.
 
So you mean two tb3 share 40Gbps bandwidth? If one reaches maximum speed the other drops to zero? If I connect the egpu directly to one of the ports, then whatever I connect to the next port on the same side effects egpu too? Please enlighten me, I do need to know this.
Seeing how in there system report there are only two Thunderbolt 3 bus devices, each at 40Gbps. Yes, there is only 40Gbps of speed on each side.
 
Seeing how in there system report there are only two Thunderbolt 3 bus devices, each at 40Gbps. Yes, there is only 40Gbps of speed on each side.

this makes sense. thank you for the info Im gonna pay attention to it.
 
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