I'm planning a CPU upgrade for an RTX 4070 system. I mostly play at 1080p and 1440p, but my graphics card often sits underused while the current processor is working at full load. The Core i5-12600KF seems like a popular pairing with the RTX 4070, but I'm hesitant to move from one aging platform to another. The Ryzen 5 5500X3D is available for my current socket, although I'm not completely confident about buying one, while the Ryzen 7 5700X3D is difficult to find locally and would be expensive. I'd also rather avoid moving to AM5 because of the additional DDR5 cost. Which option would give me the best gaming performance and help the RTX 4070 perform closer to its full potential?
2 Answers
The Ryzen 5 5500X3D itself is a strong gaming chip; the main uncertainty is usually the seller and product quality rather than the processor. If you can buy it from a trustworthy source with reasonable return protection, it should outperform a Core i5-12600KF on DDR4 in many games while letting you keep your current motherboard and memory.
The Core i5-12600KF is still a very capable processor and gives you a more well-rounded system, especially for heavier multitasking or productivity. That said, for a gaming-focused upgrade, the Ryzen 5 5500X3D should generally be faster than the 12600KF when using DDR4, so it makes more sense if your main goal is higher gaming performance with the RTX 4070.

My main concern is gaming. The RTX 4070 is currently sitting idle in a lot of games while the processor is working extremely hard, so I’d like to make better use of it at both 1080p and 1440p.