What do you want to do with your CPU?

It's tempting to just spend as much as you can afford for a CPU, but you might be better off saving some of your cash for other components. Determine your processor type and max budget based on what you need your computer to do.

Basic tasks: $50-$100 (£35-£80) range. If you’re only after a chip that will let you watch video, browse the Web, and do basic productivity tasks like word processing and light spreadsheet work, then an entry-level chip with two or four cores might be just what you need. But if you often find yourself doing more than one of those basic tasks at once, it would be better to step up a model or two. Consider a Ryzen 3, like the AMD Ryzen 3 1300X or AMD Ryzen 3 2200G, or Intel Pentium on the high end of this price range and an Intel Celeron or chips like AMD's Athlon 200GE on the low end.

Gaming: $150-$250 (£120-£220) range. If you’re primarily interested in gaming performance, you need at least a mid-range Intel Core i5 or AMD Ryzen 5 CPU. Considering that the graphics card is more important for gaming than the processor, you can save money by not getting a more powerful Core i7 or Ryzen 7 chip.

Creative media work or overclocking: $250-$350 (£220-£320) range. If you want more cores or speed for things like video editing—or you just want a fast, capable system with extra overhead for future computing tasks, splurge on a Core i7, Core i9 or Ryzen 7 chip. These are also the chips you'd consider if you want to overclock, though AMD’s lesser Ryzen chips are overclockable as well.

Workstation muscle: $400+ (£370+). If you often find yourself waiting minutes or hours for your current system to render your 3D animation or 4K video, or you’re dealing with massive databases and complex math, consider an Intel Core X or AMD Threadripper CPU. These beasts offer massive amounts of physical cores (up to 32 as of this writing) for extreme multitasking (ex: gaming at high settings while streaming and editing) or time-consuming compute tasks. Business users can consider an Intel Xeon (like the recent Xeon W-3175X) or AMD EPYC processor, but those aren't consumer friendly--or reasonably affordable.