Hi

I have a Dell XPS 8950 which is two years old (so out of warranty), and over the past week it's slowed to a crawl. I've run the UserBenchmark tests and the results say that my CPU (i9-12900K CPU @ 3.20GHz) is running at 14% speed. I've reinstalled Windows and reset the BIOS to the default options without success. What should I do now? Can I replace the CPU myself (the machine is water cooled, which may present a problem)? Is there anything special about the Dell motherboard (or anything else) that prevents me from replacing it with an identical new CPU from Intel? Alternatively, what's the best way to get it checked/repaired?

Thanks