My previous i9-13900K failed a couple of months ago, and I bought an i9-14900K because it was the fastest replacement available locally. Since installing it, temperatures have been unusually high: around 50°C at idle, 70–80°C while watching videos, and 90–100°C during gaming even with only about 30% CPU usage. The motherboard's CPU warning light also comes on. I applied a -0.065 V core-voltage offset, but it did not resolve the problem. The 14900K came from a retail store without its usual packaging, so it may have been refurbished. My system uses an ASUS ROG Strix Z790-E motherboard and a Corsair iCUE H150i Elite LCD XT 360 mm AIO. What should I check or change?
3 Answers
The missing retail packaging is worth treating as a warning sign. If the processor was refurbished or previously damaged, it could be part of the problem, especially given the history of early 13th- and 14th-generation chips. Before buying another CPU, test with proper power limits and a known-good cooler, then consider returning or exchanging the processor if temperatures remain abnormal.
Update the motherboard BIOS to a version containing Intel’s 0x129 microcode and the latest stability fixes. Also set reasonable CPU power limits instead of relying only on the undervolt. The 14900K can pull a huge amount of power on unrestricted motherboard settings, which leads to very high temperatures even during seemingly moderate workloads.
First check whether the cooler is making even, firm contact with the CPU. LGA1700 sockets can flex the processor, so an LGA1700 contact frame may improve mounting pressure. Repaste the CPU and make sure the pump is running properly. A 360 mm AIO should normally handle the chip better than this unless contact, pump performance, or mounting is the issue.
I did repaste it when I installed the replacement, but the cooler has performed poorly since I bought it. I may need to replace it even though I was hoping to avoid rewiring everything.

The BIOS was updated right after I installed the CPU, but I’ll verify that it includes the 0x129 microcode and then check the power-limit settings.