Share:

Monitoring Thunderbolt bandwidth  

  RSS

(@llamafilm)
Active Member
Joined: 10 months ago
Posts: 18
March 14, 2019 8:50 pm  

Does anyone know of a tool to monitor the bandwidth across TB bus?  In my application the eGPU usage in Activity Monitor is fairly low but I suspect maybe the bus is maxed out.  It would be nice to have actual data on this.
I have used opcm in the past on Linux, but never fully understood its output, and I'm not sure if it works for Thunderbolt.

Testing MacPro6,1 with Vega64 in Sonnet eGFX on Mojave


Quote
(@kelvin_tan)
Estimable Member
Joined: 1 year ago
Posts: 113
March 15, 2019 4:54 am  

You can use Cl!ng to test your egpu bandwidth.

It will show the bandwidth direct to only the GPU. So for example if you have a USB enclosure or other thunderbolt devices on the same thunderbolt path, and starts copying a file, Cl!ng will show a reduction in bandwidth available to the GPU.

This post was modified 2 months ago

X1 Yoga Gen3, X1 Tablet Gen 3, MacBook Pro 15" 2018
Razer Core X / Mantiz Venus
Asrock Radeon VII, Zotac Nvidia 1080Ti Amp Core Extreme, Powercolor Vega 56 reference (flashed to V64 bios)


ReplyQuote
(@llamafilm)
Active Member
Joined: 10 months ago
Posts: 18
March 29, 2019 6:42 pm  

Thanks, I hadn't seen that one.  Looks similar to CUDA-Z.  But I want to monitor bandwidth in real-time while the GPU is used by another app.
Cl!ng shows that the Vega 64 is doing 2300MB/s which seems slow.  It should theoretically get close to 4000.

opcm does work on macOS but pcm-iio.x only supports measuring PCIe device bandwidth on Skylake CPUs for now

Testing MacPro6,1 with Vega64 in Sonnet eGFX on Mojave


ReplyQuote
(@kelvin_tan)
Estimable Member
Joined: 1 year ago
Posts: 113
March 30, 2019 2:08 am  

2300 is correct. We are all getting about 2200 to 2500. TB3 is 32gbps, but Intel throttles it to 22gbps. See 

https://egpu.io/build-guides/#perf

X1 Yoga Gen3, X1 Tablet Gen 3, MacBook Pro 15" 2018
Razer Core X / Mantiz Venus
Asrock Radeon VII, Zotac Nvidia 1080Ti Amp Core Extreme, Powercolor Vega 56 reference (flashed to V64 bios)


ReplyQuote