League consistently spiking me to 100% use of CPU

PC specs, memory usage, RAM, RAM allocated, RAM usage?

From my understanding CPU activity will normally spike to 100% as your computer wants to finish things as fast as possible and use as much CPU as possible. It's when that 100% divided among all the different processes is still not enough that you can safely say your CPU is slowing you down.

Keep task manager up, look under the 'processes' tab and sort by 'CPU'. Play through a game and make sure your game client is the only thing drawing a significant amount of CPU. If something else pops up at the top of the list then that's your problem.