Digital Foundry does really great deep-dives on the software side of things. A channel like GamersNexus is great for getting a sense for how a new CPU or GPU stacks up to other models. DF is great for looking at game performance in a specific title, and which settings to tweak for optimized performance with various graphics cards.

Edit: and they do the same for major console titles, plus cross-platform and cross-gen comparisons.