HeatMon
Accurate CPU Temperature Monitoring Software
HeatMon is accurate CPU temperature monitoring software that displays the temperature per core on the CPU (on-die sensor / DTS – Digital Thermal Sensor) and can read sensors near the CPU socket on the motherboard if supported (socket / CPU package sensor).
Almost all modern processors (Intel, AMD) already have internal sensors in the chip. This is the most accurate way to monitor core temperatures because it is located directly near the CPU's heat core area.