Does 60FPS+ make a huge difference in SINGLE PLAYER games?

"Single player" vs "Multiplayer" isn't always a proper comparison. FPS matters in a fast paced games, where a lot of stuff happens on your screen. It just happens that multiplayer competitive games are usually exactly like that. Having bad motion clarity can affect visual quality, as well as affect your reaction, if it's needed. If you are playing story games, or smth with a low-paced combat (could be summarized as "smth you use to play with gamepad"), it won't matter that much. I own RTX 4090 myself, and personally I think 90 fps is a sweet spot. I definitely notice smth below 60. I've been using OLED monitors for a while now, so 60-90 feels much better as well (since OLED has much better motion clarity). So I can't tell you it's good to limit FPS to 60 regardless of the game. In something "The Last of Us" 60 fps will be just fine. In a racing game, I'd like to have a bit more. In FPS game, something with first-person view and shooting or such, I'd like to have 144+. All in all, what I can advise you is the following: - Test every game for yourself. - Try overclocking your GPU with limiting max power. I did the same with my 4090 Strix. It is limited to 300w and is clocked to 2820. It was clocked to 2820 core speed out of the box, but with default power usage. I played with afterburner a bit, and found out a perfect balance of sub 70% power with \~2800 clock speed. I don't care about electricity bills, but heat and less fan noise is important. - Don't disregard your monitor quality and it's motion clarity. Depending on the tech it's using, it may greatly affect the result. I know it might be late to think about it (but you can always sell/buy stuff), but sometime better monitor+worse GPU is a better combo. Both efficiency-wise and visual experience-wise.