I am trying to understand how the PCIe 3.0 4x lanes of thunderbolt 3/4 impacts my ability to drive multiple high resolution displays through a eGPU. I want to use a eGPU to drive (3) external displays: (1) 5K display and (2) 4K displays. Let's take an extreme case to illustrate this question, I am looking at the Nvidia Quadro T1000 which supports driving (4) 5K displays at 60hz. Will this max out the PCIe 3 4x link of thunderbolt or is a lot less data transmitted between the CPU and GPU than between the GPU and monitors?
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
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A lot less data transmitted between CPU and GPU than between the GPU and monitors. So go ahead and connect four 5K displays.
A 5K display is 28 Gbps (933 MHz x 30 bpp). Four of them is 112 Gbps. That is definitely not coming from PCIe or Thunderbolt.
The CPU tells the GPU to draw a line or copy a bitmap. The GPU makes the change in its VRAM. The GPU streams the VRAM contents to the display 60 times per second.