My current system has a Ryzen 7 5700X, Radeon RX 7800 XT, MSI B550-A Pro motherboard, 32GB of Kingston DDR4 memory, and an 850W Chieftec PSU. It began suffering hard freezes earlier this year, requiring the system to be completely powered down before it would start again. After reinstalling Windows, replacing the PSU, and eventually replacing the motherboard, the problem improved but did not disappear.
I still get occasional crashes, BIOS settings sometimes reset, and Windows has occasionally disabled the graphics card in Device Manager. Event Viewer also reports intermittent Cache Hierarchy Errors, which makes me suspect that the CPU may be failing.
Moving to AM5 is not realistic because DDR5 is expensive, and I only replaced the motherboard a few months ago. A replacement Ryzen 7 5700X costs a little over $170 locally, while a Ryzen 7 5800X costs around $250 and offers only a small performance increase. A Ryzen 7 5800X3D costs roughly $400–$420, which seems difficult to justify for an older AM4 platform. The more affordable X3D chips, such as the 5600X3D or 5700X3D, do not appear to be available here, even second-hand.
Would it make more sense to buy another 5700X and keep the system going for a few more years, or is the 5800X3D worth the high price as the final upgrade for this platform?
2 Answers
Cache Hierarchy Errors can point toward a failing CPU, although it is still worth confirming with stability tests and checking BIOS settings first. Given your local prices, I would replace it with another 5700X and save the money. Spending around $420 on a 5800X3D for roughly a 10–15% gaming improvement is hard to justify, while the regular 5800X would only provide a minor gain over what you already have.
If you could find a reasonably priced 5600X3D or 5700X3D, either could be an interesting gaming-focused option, but the upgrade would depend heavily on the games and resolution. At 1440p with an RX 7800 XT, the difference from a 5700X may not be dramatic in many titles. Since the X3D models are unavailable locally—even used—the replacement 5700X is the practical choice.
I checked both new and used listings, but the smaller X3D chips seem completely unavailable here. The only one I can actually find is the very expensive 5800X3D.

That makes sense. It feels strange to replace the CPU with the same model without gaining performance, but the cheaper replacement seems much more sensible than paying a premium for a small upgrade.