Ideal bandwidth for Surface Pro as second monitor

[dougw03]

Hello, I have configured my Surface Pro 8 to be my second monitor and am using an ethernet crossover cable with GigE on both ends. I want to use the surface pro at full res (2880×1920), 60Hz, 4:4:4 and no quality compression. Even with GigE, I’m finding that the display stutters quite a bit and can be laggy. Do I need to upgrade to 2.5G (or 10G?) to make things work smoothly? Thanks

[spacedesk Christian]

Hi @dougw03,

Sending uncompressed data at high resolution (2880×1920) and frame rates of 60 Hz (60 frames per second) is still too heavy a burden for many networks even nowadays.

You can do the calculation for yourself:
– Every pixel has 3 bytes (when using 4-4-4)
– One frame needs 5,529,600 pixels (2880×1920 resolution)
– One frame needs 16,588,800 byte (5,529,600 pixels x 3 byte)
– One second needs * 995,328,000 byte (16,588,800 byte x 60 frames)
– One second needs * 7,962,624,000 bit (995,328,000 byte x 8 bit)

Your maximum raw network bandwidth requirement needed for this scenario is 8 GBit/sec
In addition to this, there comes the delay caused by CPU load doing JPEG image compression.
At JPEG 100% and 4-4-4 there is maximum CPU load for image compression but still minimum reduction of image size.

[dougw03]

Thanks for the derivation, Christian. So I’ve tried dialing down my settings to 0 image quality and low bit color and it still feels like there is a noticeable amount of latency on my 1GbE connection. I don’t want to drop to 30Hz because that will defeat the purpose. I monitor the statistics and it seems I can’t ever get above 20fps. Does Spacedesk cap FPS? Is there anything else I can adjust to make this seem like more of a seamless connection or do I need to go buy some 10GbE adapters or is this just a limitation of the software? Thanks

[dougw03]

Bump

[spacedesk Christian]

Hi @dougw03,

How are you measuring the fps?
What content are you playing while measuring fps?
Please give us more information about your Primary Machine running spacedesk Driver.
To do so, please send us the diagnostic info of your primary machine.

Just open the spacedesk Driver Console -> Diagnostics, click the “Save All Information” button.
If message box appear, please click “Yes” and it will restart as Administrator, then click again the “Save All Information” button.

PS: Saving all information will take a few seconds, then please send us the whole folder which contains all the diagnostic logs collected.
Please right-click the folder -> Send to -> Compressed (zipped) folder, then attach the *.zip file in your next reply.

[dougw03]

Hi Christian,

I was just going based on the stats at the bottom in the application itself. I use my second monitor for very basic office tasks like word, excel, web browsing, etc (no videos/gaming). My hope was that I could have a seamless connection with GigE on both ends. The primary machine is a Dell Latitude 5420 Core i5 16GB RAM.

It seems diagnostic collection was turned off but I attached the zip file in case it helps. I have turned diagnostic collection on and can reupload once I have more data.

Thanks for your help
-Doug

[spacedesk Christian]

Hi @dougw03,

Unfortunately, the file exceeds the allowed size.
Could you maybe try to split the contents of the diagnostics into 2 folder and just upload 2 zipped folders.
Or maybe upload the zip file in the dropbox or other file hosting services and just send us the download link.

[dougw03]

Disregard – see next reply

• This reply was modified 1 year, 4 months ago by dougw03.

[dougw03]

Hi Christian, I just upgraded to 1.0.7.3 and the lag is pretty much gone and now I have 50+ fps. You can disregard my request for now. Thanks anyways

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