hanncher,
I see that you're a new Member, so on behalf of Tom's Moderator Team, welcome aboard!
hanncher :
At Intel's site, the Tcase value for the i5 4460 is 72.72 degrees. What does this mean?
Here's Intel's definition:
"TCASE
Case Temperature is the maximum temperature allowed at the processor Integrated Heat Spreader (IHS)."
That would seem to be a pretty straight forward specification, except that unfortunately, it's not quite as simple as Intel would like everyone to think.
Tcase is a
factory only temperature measured on the external surface of the processors "Case" or Integrated Heat Spreader (IHS) where the cooler is seated. Tcase is only tested on "Engineering Samples" in Intel's labs. There is no actual Tcase thermal sensor on retail processors, so the end user such as you and I have no way to measure Tcase.
Like everyone else, when users look up their processor's Thermal Specification on Intel's Product Specifications website, they don't realize what Tcase actually means. Since there are numerous utilities for measuring Core temperature, everyone assumes that Tcase must be Core temperature.
Tcase is not Core temperature.
Core temperature is instead measured by individual Digital Thermal Sensors (DTS) located at the heat sources near the transistor "Junctions" inside each of the Cores. Since Tcase is a factory only
external temperature measurement which is
not in close proximity to the heat sources, Core temperatures are significantly higher than the temperature on the Integrated Heat Spreader (IHS), which is Tcase.
Desktop processors have
two Thermal Specifications; Tcase, which is used for designing CPU coolers, and "Tjunction" which is also called Tj Max (
Temperature
Junction
Maximum) or "Throttle" temperature. Throttle temperature (Tj Max) is where the processor will reduce Core speed and voltage to safeguard against thermal damage, so Tj Max is the
limiting Thermal Specification;
not Tcase.
The Tcase specification is
misleading because users assume that's as hot as their Core temperatures are allowed to get, when once again,
Tcase is not Core temperature. Since Tj Max is shown in the Datasheets but
not on the website for 6th Generation and earlier processors, Intel does
not tell you that the
limiting Thermal Specification is
not Tcase; it's Tj Max, which for your i5 4460 is 100°C.
See page 76, Table 27, 2nd row, 4th column; TCC Activation Temperature:
Desktop 4th Gen Intel® Core™ Processors Datasheet, Vol. 1 -
https://www.intel.com/content/www/us/en/processors/core/4th-gen-core-family-desktop-vol-1-datasheet.html
For your 4th Generation Haswell processor, Core temperature is typically a minimum of about 10°C higher than Tcase, which would correspond to about 82°C. Since you're running at 70 to 75°C, you still have some headroom. However, if it's winter where you live, then come summer, your thermal headroom will decrease as Ambient (room) temperatures increase.
Here's the operating range for Core temperature:
Core temperatures above 85°C aren't recommended.
Core temperatures increase and decrease with Ambient temperature.
Idle temperatures below 25°C are generally due to Ambient temperatures below 22°C.
Highest Core temperatures occur during stress tests, rendering or transcoding, but are lower during less processor intensive workloads such as applications and gaming. Core temperatures can vary greatly among games due to differences between CPU and GPU workloads.
If you'd like to learn more, then read this Sticky:
Intel Temperature Guide http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html
Once again, welcome aboard!
CT