Core i7 vs. Core i9: Which high-end laptop CPU should you buy?

When you're shopping for a high-end gaming laptop, one fundamental choice is whether to buy a model with a Core i7 or a Core i9 CPU. The Core i7 CPU is powerful, but the Core i9 is supposed to be the topmost performer, the extreme machine--usually with an upcharge to match. When you're focused on the CPU it's about the performance, and two major factors affect that: the megahertz or clock speed the CPU runs at, and the amount of compute cores it has. In laptops, one more very important constrain...