PowerEdge: Does Running the CPU at High Temperatures for Extended Periods Impact its Quality and Lifespan

Users may report that their CPUs are consistently running at temperatures at or above 70°C (158°F) even when there is a low load on the CPU.

The leading processor manufacturers intentionally design their components to function at high temperatures throughout their lifespan. They do so based on their understanding of the dependency on system fan power and cooling capabilities. For instance, if Intel or AMD specifies a maximum CPU temperature of 95°C (203°F), it means that the processor can operate at that temperature limit without negatively affecting its lifespan. This is provided the CPU does not exceed that temperature threshold.

In situations where a processor runs at high temperatures during idle periods, it is because the system fan power is being conserved. The total power consumption of system fans can range from 85 W to over 200 W, and conserving power plays a crucial role in reducing fan power consumption without compromising the reliability of the system components.

See Intel's article on Intel CPU temperature. 
Quote from article：

"Could my processor get damaged from overheating?
It is unlikely that a processor would get damaged from overheating due to the operational safeguards in place. Processors have two modes of thermal protection, throttling and automatic shutdown. When a core exceeds the set throttle temperature, it reduces power to maintain a safe temperature level. The throttle temperature can vary by processor and BIOS settings. If the processor is unable to maintain a safe operating temperature through throttling actions, it automatically shuts down to prevent permanent damage."

Different CPU models have different "DTS Max" and Tcase.
"Digital Thermal Sensor max value (DTSmax) is the junction temperature limit for the CPU."
There is no specific unified definition for high temperature.
See Ark Intel's article. 
For example:
Ark Intel Gold 6430:   DTS Max 90°C (194°F) Tcase 72°C (162°F)
Ark Intel Gold 5415+   DTS Max 99°C (210°F) Tcase 78°C (172°F)
 
For a detailed explanation on this topic, see the video featuring Dell's thermal control architect.
It is ok to have a hot component or hot exhaust temperature:

If a lower temperature is wanted, choose custom cooling options to lower the CPU temperature at idle and under load, but is at the expense of more system power consumption. This provides no apparent benefit (in terms of CPU reliability or system reliability).

For Instance:
(See the iDRAC9 User Guide-Optimizing system performance and power consumption for more detail instruction.) 1. Default Thermal Profile + BIOS System profile--Performance. 
        This setting raises the fan speed baseline and increase fan speed for cooler CPU temperatures.
2. Change Thermal Profile from default to Maximum Performance.
        This option behaves similarly to Option#1.
3. Change "fan speed offset" from default off to low
         By adding 25% PWM based on the minimum fan speed requirement
4. Custom Minimum fan speed-Set higher minimum fan speed than minimum fan speed calculated by iDRAC Thermal.
5. Set lower "Maximum PCIe Inlet Temperature Limit" or lower "Exhaust Temperature Limits"
      This may result in higher system fan speed, used for third-party PCIe card that requires a lower temperature.

For Dell PowerEdge servers, the thermal design regarding CPU temperature is as follows:

1. iDRAC thermal reads the CPU's DTS Max as CPU critical Max Threshold.
2. Dell PowerEdge thermal engineers perform thermal testing on different configurations and determine an offset (like 10°C [50°F] or 15°C [59°F]) during platform development phase to define the CPU target temperature (DTS Max - Offset).
3. When the CPU temperature reaches or approaches the defined target temperature, Closed-Loop fan control responds by adjusting fan speed linearly based on the thermal engineer's test results. For example, if the CPU temperature remains at or over the target temperature, the fan speed continues to increase until it reaches 100%.
4. If increasing the fan speed to 100% is not effective in controlling the CPU temperature, the power consumption and frequency are lowered to reduce heat generation. Like when CPU temperature reaches 5 degrees below DTS Max, a proper CPU power cap is set.

• In specific scenarios, such as a fan failure, a suitable CPU power cap is set once the CPU temperature reaches the target temperature only.
• For certain heavy configuration, a proper CPU power cap is set preemptively when the ambient temperature exceeds the predetermined threshold, even if the CPU temperature is still far from the target temperature.