The previous forum had many posts which specifically addressed graphic computer capabilities versus gaming systems. And frankly, I’m not entirely sure if the issue has ever been finally resolved. Processors differ from manufacturer to manufacturer and may vary in different model units from the same company as well. The processor does have an impact on performance and functionality, however you should be able to find a palatable approach to your dilemma without the need to replace your hardware.
Here are a few links to point you in a direction to get more information on the subject.
https://sites.google.com/site/sketchupsage/faster/
http://help.sketchup.com/en/article/36235
https://sites.google.com/site/sketchupsage/faster/computer
https://sites.google.com/site/sketchupsage/problems/gpu
You may also want to read this…(not suggesting you want to buy another system, but this thread features a discussion on what systems are better for SketchUp use).