Swapping in a new hard drive into the PS4 is relatively easy—the question is, what sort of hard drive should you swap in? You've got SSDs, which are speedy—but also expensive. And then you have hybrid drives to consider, too.
This video by Tested runs speed tests between all three drives, from boot up times to game loading and more. It also breaks down what the pros and cons of the different drives are—an SSD might not be the best choice for you, even if it's faster in some cases.
What type of hard drive will you go with?