Not necessarily. “Work” could be headless compute (e.g., folding@home, BOINC). But if the workload includes video encoding or GUI rendering, a PCIe Gen2 GPU (like GTX 780 Ti) is recommended.
This guide assumes "GB2" refers to a computational workflow (like geospatial analysis, simulation, or data processing) where the CPU is the primary workhorse, not the GPU. cpu gb2 work
Proxmox Cluster Setup with Multiple Machines for Homelab Ecosystem Not necessarily
They communicate through "highways" on the motherboard called cpu gb2 work