While most virtualization tools only need a capable CPU and RAM, having a dedicated GPU can improve graphics performance and speed up certain tasks, such as video encoding or rendering.
Most modern GPUs from NVIDIA or AMD can be used with VMware and VirtualBox, with high-end models like the NVIDIA RTX 4090 providing the best performance.
However, for basic virtualization tasks, a mid-range or entry-level GPU should suffice, and depending on your computer’s specs, you might need none at all.