Does it matter which TB3 I use on a 2019 Macbook Pro 16"?
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Does it matter which TB3 I use on a 2019 Macbook Pro 16"?  


New Member
Joined: 10 months ago

I just found out not all TB3 ports on the 2019 Macbook pro 16" are equal. I hooked up a gigabit ethernet to the front right side port on my macbook and only got 60mb download vs 800mb download on the back left port.

I currently have a razer core x hooked up to the back right TB3 port. Is this okay or should it be hooked up to a different TB3 port? 

I was unable to find out how many PCIE lanes each port has on Apple's website so i really have no idea. I wonder why Apple makes it so difficult to figure this out.

This topic was modified 10 months ago

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.


Active Member
Joined: 1 year ago

The 2019 MBP 16" has two TB3 controllers, each managing two ports on either side.

It's best not to share the TB3 controller where your eGPU is plugged into with any other accessories. Otherwise you may experience stutter or degraded performance.

I hook up my dock (KB+M, speakers, SSDs, display) to the back right port. When I want to game I boot into Windows, plug in my eGPU to the back right port and switch display inputs to the eGPU.

This post was modified 10 months ago

2019 16" MacBook Pro (RP5300M) [9th,6C,H] + EVGA GeForce RTX 3090 XC3 ULTRA GAMING @ 32Gbps-TB3 (Sonnet eGFX Breakaway Box 350W with Corsair SF750 PSU, Akasa 12cm Viper Fan & Mantiz Venus 87W PD FW) + Win10 20H2

Eminent Member
Joined: 3 years ago

@jav, Can we get a bit more info on this?  I have a very odd use-case but do want to maximize the use of eGPUs for now. 

I have a total of 31 or so usb devices i keep hooked up via a combo of apple multimedia adapter (version 2) has more bandwidth but looks the same.. Thanks apple!!!  - and the rest are spread across the TB3+ dock from caldigit.  

I also have the 16 inch.

Would love to see a diagram or something.. 



2018 MacBookPro 15 in. /w Touchbar - i9 - 32gig ram - 1080 Aorus 1080 Gaming Box - Sonnet-Breakaway550 with GTX 1080 - Still need to get both of the GTX 980TI working for 4 GTX total cards