Issue with the processor.
Issue with the processor.
The issue lies in the motherboard's specifications, not just the CPU speed. The problem occurs when trying to run at 4425MHZ across all voltages, but it functions smoothly at 4400MHZ above 1.35V. Your cooler handles the heat well, and the PSU supports the load. The bottleneck is likely the motherboard's clock speed limit, not the CPU alone.
It's not the case. Most processors have a limit on their multiplier. I'm facing the same issue with my top-of-the-line processor and overclocking the motherboard, but I can't exceed a certain value. Changing the BIOS is possible, though it carries risks since it impacts other components. Motherboards aren't crucial for overclocking as long as they don't overheat.