Hi,
yes, a more powerful computer will always help, but I am not sure if this is the graphic card or the processor itself that would be the bottleneck here..
I moved to a new laptop this year, and it does make a huge difference indeed... not just Unity, but also xcode for example, I can now compile and run on a device under 3mn, wereas before it was litterally 15 mn or more...
bye,
Jean