ReadyNAS Pro 6 Temperature

Hi all,
CPU temperature on Ultra 2/4/6, Pro 2/4,
Display 50C for DTS reading if CPU temperature < 50 degree C,
The below is all about CPU temperature reading:
1. Intel processors have two temperature monitoring mechanism, thermal diode and Digital Thermal Sensing (DTS)
2. Thermal diode is not accurate, its accuracy is prone to PCB layout, component variation, to use it, the system needs to be calibrate individually.
3. DTS reading is relative temperature compare to Tjunction. The Tjunction is maximum temperature the CPU can safely reach, beyond Tj, the CPU may be damaged. Linux coretemp driver translates relative temperature to human readable temperature, i.e. in Celtics degree.

We decided to use DTS for RNDU2/4/6, Pro2/4, the following must be taken care when DTS is used:
1. During a period time after boot, DTS reading may be shown as “Resource temporarily unavailable”
2. During a period time after boot, DTS reading may be very low, e.g. < 30C
3. When CPU is overheating, DTS reading may be shown as “Resource temporarily unavailable”, Also kernel log shows CPU speed throttle kicks in.

Because of above reasons, we decided to do following:
1. For any DTS reading less than 50C or “Resource temporarily unavailable”, display CPU temperature as 50C, this is per Intel’s guide line: Anything below 50C is OK and should be treated as reference only
2. CPU overheating shall never happen, guaranteed by hardware design, we stress CPU to its TDP under 40C room temperature. So there will be no overheating in promised operational range. Software does not need to handle overheating reading of “Resource temporarily unavailable”.
3. Intel CPU has two hardware mechanism to prevent overheating should we fail our hardware guarantee(which is very unlikely): CPU speed throttle and CPU thermal shutdown