8700k one core is hotter than the others

[Randallel]

I know that Coffee Lake has a single core boost. Does anyone know which core that would be? Is it core 0? I'm curious because core 5 is hotter than the rest of my cores.

 

[krzyimprt]

Poorly applied paste under the heatspreader by Intel. My 6600K first core has a 5-7c difference compared the other three. Nothing to sweat over though, as long as temps are in check.

 

[CompuTronix]

Randallel,

Core #0 runs at the highest Turbo Boost frequency, and handles the single threaded workloads.

Intel's specification for Digital Thermal Sensor (DTS) accuracy is +/- 5°C. Although sensors are factory calibrated, this means deviations between the highest and lowest Cores can be up to 10°C. Deviations on processors using Turbo Boost might exceed 10°C by a few degrees. Sensors are more accurate at high temperatures to protect against thermal damage, but due to calibration issues such as linearity, slope and range, idle temperatures may not be very accurate.

If the deviation between your highest and lowest Cores does not exceed 10°C, then your CPU meets Intel's specifications. If the deviation between your highest and lowest Cores exceeds 10°C, then you
have grounds for submitting your processor for an RMA replacement, due to excessive temperature deviations between Cores.

You might want to give this a read: Intel Temperature Guide http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html

CT