This thread has touched on 'normal', 'safe' and 'maximum' CPU temperatures. If you came to this thread (as I did) in a quest to find out what these temps are, with regard to the Xeon family, the following may be of help.
As h9826790 pointed out, all of the operating norms posted here are well within the Xeon's range. 'Normal', of course, varies for each user, so unless a reference point is set for comparison (like "idling with MacOS-only running in a room with ambient temperature of 65˚F.") determining 'normal' is next to impossible. According to
Intel's page on Xeon thermal management:
"Intel can't give a specific operational temperature range of an Intel® Xeon® Processor because it will depend on the maximum performance of the heatsink used [and] the way the fans are controlled in a system (which can vary the performance of the heatsink)."
Nonetheless, Intel gives ≈75˚C. as a 'maximum case temperature' in their
table of Xeon thermal characteristics.
A Puget Systems review, based upon their in-depth studies of the operational thermal characteristics of the Intel Xeon family, made the following observations:
"We know from both experience and explicit testing that modern Intel CPUs (at the very least Sandy Bridge, Ivy Bridge, and Haswell) can run at their maximum Turbo Boost frequency all the way up to 100 °C. While there may be a tiny performance difference between a CPU running at 30 °C and one running at 95 °C, our testing has found that the difference is minuscule. In fact, even after running benchmarks dozens of times the difference is so small that it is essentially nonexistent."
and:
We were very surprised when our testing showed that while the minimum CPU load frequency started to drop as soon as the CPU hit 100 °C, the average CPU frequency didn't drop by more than .1GHz until the CPU was overheating more than 30% of the time. In fact, Intel CPUs are surprisingly good at being able to handle this much heat with such a small reduction in the average frequency.
concluding:
For the average system, our rule of thumb at Puget Systems is that the CPU should run around 80-85 °C when put under full load for an extended period of time. We have found that this gives the CPU plenty of thermal headroom, does not greatly impact the CPU's lifespan, and keeps the system rock stable without overdoing it on cooling. Lower temperatures are, of course, better (within reason) but if you want a target to aim for, 80-85 °C is what we generally recommend.
I set my fan controls to keep my CPU-A core temp below 92˚C. when doing extended Handbrake encoding or other CPU-loading tasks.
I hope this information is useful.