The tcase is given for each cpu on the Intel website, the tcase for the i5 2400 is
72.6C, the i3 2100 probably has the lowest tcase at 69.1C. Given the location of the would be tcase sensor, tcase is always lower than tjmax (sounds like the discount store).
YES. TCASE lower than TJMax -- by a pile.
FIRST -- let me apologize for this, because I almost spawned a falsehood. SHINTAIDK is correct about some of this.
I went back to search for articles I'd read between 2004 and 2006 [which I should have printed to PDF and saved in an archive. . . But I didn't.]
TCASE "Max"(?) is a temperature spec BELOW which the processor would never throttle.
According to some information I dredged up (all in the last hour or so), a TCASE value in excess of the processor spec (on the Intel processor spec-sheet) defines a range up to TJMax considered to be an "overheating condition."
The TJMax value will indeed cause "throttling down," but the total shutdown of the processor is not far above the throttling threshold.
It irks me that Tom's Guide, Anandtech and other sites aren't keeping a total library of their published articles. In my searches, I find a lot of forum posts -- with some "experts" answering. But even so -- these knowledgable gurus also can be wrong and make mistakes.
Here's a thread at Tom's forums, with some insight by a contributor named "Computronix:"
http://www.tomshardware.com/forum/254214-29-tjunction-x6800
Note particularly his paragraph here:
[BEGINNING OF QUOTED EXCERPT]
Don't feel like you're alone; many others are also confused by Intel's thermal specifications. To answer your questions, technically speaking, no and yes. Intel's papers go to great lengths explaining how they test CPU temperature in the lab to measure Tcase Max, which if you might have noticed, is defined to the tenths of a degree, while Tjunction Max is just a round figure such as 85c or 100c.
To put it into simplified "real world" terms, the practical difference is that Tcase Max applies to operating temperature, while Tjunction Max applies to shutdown temperature, which is strictly for overtemp protection, so you don't toast your transistors.
As soon as you exceed Tcase Max, you've reached an overtemp condition, in which you can still push the temperatures even hotter, until the processor throttles, and then finally shuts down at Tjunction Max.
Think of it like the temperature guage in a car, except the guage has three needles; one CPU needle which is alwyas 5c lower than the two Core needles. We all know the red zone, which begins at 60c-65c-65c means hot, but if you keep driving until the needles are pegged at 80c-85c-85c, then it's going to shut down.
[END OF THE QUOTED POST]
And again -- my apologies, but I thought I noticed throttling during last year's over-clock project based on TM1 [and/or] TM2 "ENABLED" on my system -- coinciding with temperatures in the mid-80's centigrade. When I disabled the settings, the throttling at the same OC settings did not occur -- was not apparent in the monitoring software. Further, I think I know the difference between "real" throttling back of a processor core and the unloading of the processor that occurs between iterations of either IBT or Prime95.
But the key point here -- and as discussed on the 2009 thread to which I posted a link (above) -- this has always been confusing to people. The forum thread notes that Intel has never been entirely clear or helpful about these standards, and many people find themselves confused about them. Here for instance is an actual published article, attempting to explain the specs, temperatures, standards and "maximums:
http://www.techreaction.net/2009/10/14/guide-to-understanding-intel-temperatures/
Now there had been some other insights of colleagues here posted last year, to the issue that similar conditions that you might think are "throttling back" occur just for voltage settings that are a hair insufficient.
For myself, I simply chose as my limit an approximate average of Tj sensor temperatures at the TCASE 72.6C value. This, of course, meant that I might have reached a stable OC of 4.8 Ghz (or thereabouts) with higher temperatures. But I simply chose to stop at that 72.6 value. Which also means that the actual TCASE temperature for those overclocks was 5 to 10C below the peak temperature.
Just a footnote about my Sandy Bridge OC'ing -- or for that matter -- any OC'ing. Voltage is always a more substantial threat to processor life than temperature. Point being -- given my arbitrary ("pussy") choice to keep Tj sensor temperatures below ~75C, everybody here knows that as voltage goes up, temperature goes up. And I had chosen to limit my load voltage to approximately 1.35V. [In fact, the unloaded voltage while the processor is still at "turbo" speed is higher than that. And, also in fact, my unloaded voltage would actually reach around 1.37V]
If I wanted to volt the processor higher, we would all agree that there was plenty of "wiggle room" on the temperature. But I DIDN'T want the core voltage to exceed the levels I mentioned. It wasn't the temperature that stymied me: It was my self-limiting voltage choices.
Best computer I've ever had, though. Hasn't crashed or malfunctioned in any way since before I finished the stress-testing last year.