koperan,
Intel’s specification for Digital Thermal Sensor (DTS) accuracy is +/- 5°C. 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. Although sensors are factory calibrated, issues such as linearity, slope and range can affect accuracy. Sensors tend to be more accurate at high temperatures to protect against thermal damage, so idle temperatures may be less accurate.
Since the sensor deviation between your highest and lowest Cores is 9°C, your processor is within Intel's specification. Also, you might want to read this:
Intel Temperature Guide -...