CPU temp

Does anyone know what is an acceptable operating temperature for a CPU
is?

the SiSoftware reporting tool says I have a CPU temp of 55.1°C

is this OK or too high?


More specific details:

Processor: Athlon M4 (Thunderbird) 650-1.4G 1.7-1.8V

Model : AMD Athlon(tm) Processor
Co-Processor (FPU) : Built-in
Speed : 903MHz
Model Number : 903 (estimated)
Performance Rating : PR1201 (estimated)
Type : Standard
Multiplier : 9x
Generation : 7th (7x86)
Model Information : Athlon M4 (Thunderbird) 650-1.4G 1.7-1.8V
Revision/Stepping : 4 / 2 (0)
Stepping Mask : A4..A8


Temperature Sensor(s)
Board Temperature : 25.0°C / 77.0°F
CPU Temperature : 55.1°C / 131.2°F
Power / Aux Temperature : 35.7°C / 96.3°F