As with anything technical this is true but misleading. On a CPU basis this is correct. Fusion can only use 1 CPU (or core) but unless that’s the only thing your computer is doing, the other things running can impact Fusion performance by using cycles from a single core or causing memory swapping on low memory machines (less than 32Gb Ram).
Additionally, gaming computers are not just about multi-core CPUs. One of the primary performance benefits of a gaming computer is getting a dedicated GPU (graphics processing unit) with dedicated graphics RAM. Your general purpose computer likely uses a graphics chip that shares CPU & RAM with the main computational tasks. Gaming computers do not do that.
Fusion does benefit from a dedicated GPU for things like smooth viewport navigation, handling complex assemblies with high-resolution visual effects, and in areas like CAM simulation. These are areas you directly interact with and notice as you use Fusion unless you don’t do things like run the simulation or turn your model or use a hi-res monitor (like that 4K one that’s pretty standard now even for low & mid-range computers).
A dedicated GPU enables better performance with complex models, offering higher frame rates for zooming, panning, and orbiting. But if you don’t do any of that, then sure, skip the gaming computer. High-end GPUs manage effects like anti-aliasing, reflections, and ambient occlusion without slowing down the design workspace. So even though Fusion isn’t using the extra cores of the CPU, it is definitely going to feel faster and smoother on a gaming computer with an Nvidia graphics card vs the usual generic embedded Intel video chip set.
Fusion’s “Fast mode” simulation, uses dedicated GPUs to significantly speed up toolpath verification, which reduces processing times significantly and in some cases allows you to process that toolpath that otherwise might stall the computer altogether.
That’s the not simple explanation why gaming computers can make a difference in your Fusion experience even if Fusion can’t use all of its capabilities (multi-core CPUs) because not everything can be handled only by the CPU and gaming computers are not just multi-core computers.
As a general recommendation, a gaming computer already has a bunch of stuff that you can add to a more general purpose computer to make Fusion faster but saves you from having to do on your own.
It’s just like cars. I don’t need a Lexus to drive cross country but it’s definitely a better user (driver, passenger) experience than a Ford F150.