My CPU reads the core temperatures wrong for some reason, normally it wouldn't bother me but I've noticed that its reading them so wrong its throttling. At my typical load temperature of 60C, the cores take a temperature of 105C. This makes it cut the core clock down.
I've tried turning off thermal throttling in my BIOS (Asrock Extreme 4), but it still does it.
What program are you using to monitor temps? Are you overclocked? Are you using an aftermarket cooler? If it's downclocking you then there's an issue. I would not recommend turning off thermal throttling.
Core temp, OCCT, Speedfan etc. They all display wrong. Yes OC'd but it happens at stock clocks too. Cooler is a 2013 H60.
The temperature isn't actually anywhere near 100C, it just reads incorrectly and I have no idea how to fix it. I can feel the air coming out of the radiator is only slightly warm, and it has no reason to get to 100C since I've re-installed the cooler 3 times so its on right.
In the Thermal Status section of RealTemp, it will report if your CPU is reaching the thermal throttling temperature. It will show either LOG or HOT. That's just more confirmation of what is already obvious. Your sensors are fine.
Slightly warm air coming out of the rad and an overheating CPU is a sign that your heatsink is not working like it should be. It's either defective or not attached properly. What sort of thermal paste did you use when you re-installed it? Put the Intel OEM cooler back on to confirm that your CPU sensors are working fine.
The cooler works fine, had it on two processors before this. The CPU isn't overheating because the 'CPU' temperature is correct, its just the core temps that are wrong, plus I'm pretty sure it would have died by now since its been running at 100C+ for a long time.
Intel CPUs do a great job of running at just a hair under the thermal throttling temperature for a long, long time without ever dying. That's the whole purpose of thermal throttling. The thermal shut down temperature is not until approximately 130C so these CPUs can run reliably with the core temperature in the 100C to 105C range. Here's an example:
Intel individually calibrates each core temperature sensor before they ship a retail CPU. I haven't seen a single screen shot anywhere of a retail Core i CPU with 1 bad temperature sensor let alone 4 bad sensors. It is far more likely that your cooler has failed.
The core temperature sensors are contained within the CPU so it doesn't matter what motherboard or bios version you are using. Monitoring software reads the temperature data directly from the CPU.
Intel stopped trusting the motherboard based temperature data years ago. That's the whole reason they went to multiple temperature sensors on the core and why they also individually calibrate them. Trust what your core temperature monitoring software is telling you. When a cooler is not mounted correctly or if it fails, the core temperatures can increase instantly. If it is mounted correctly with an adequate amount of thermal paste then my guess would be that the pump is failing.
Do some Google searching. These units do fail. Here's a guy that replaced the coolant and fixed his.