Solved Confusion with Tcase and TjMax

[Dude]

Hello, I'm like the title says a little confused. I have done some slight overclocking on my system

CPU from 3.0 to 3.6

RAM from 1600 to 2133

Yesterday I was in another thread and another member was about to run Intel Burn Test. He ran it standard first, then I suggested Maximum 5 passes because thats how I ran it for mine. I went from this tut
http://www.sevenforums.com/tutorials/220743-cpu-stress-test-using-intelburntest.html when I checked my system .In the tut under requirements I went to my processor for Tcase and found my Tcase is 67.4C. I always assused for Intel I needed to watch TjMax which is 105C for my cpu (I would never want to actually go that high). So I ran the test with these results. My temp went in the upper 60's for cores 0-2 and 71 for core 4. It passed but I'm still wondering was it bad to go past 67.4? My normal idle is in the 30'sC and usually never go higher than 63C playing games.

I am going to get a better cooler, my question is what is actually the highest safe temp for my proccesor.
http://ark.intel.com/products/65509/Intel-Core-i5-3330-Processor-6M-Cache-up-to-3_20-GHz

 

[paulpicks21]

Hey Dude, the Ivybridge CPU's can run fairly hot, Yes 105C should be when the PC shuts down to save any damage to the CPU, I certainly would not recommend getting close to that, but even in the 80's will be fine.

Personally I prefer to keep things between 60-70C, when overclocked, but that's just me and it's pretty cool where I live.

Sounds like everything is just fine for you right now.

 

[Dude]

Thanks Paul, trying to get all my ducks in order for when I get a K cpu

 

[essenbe]

The difference is TCase is the temp in the exact middle of the CPU. I really don't believe there is any software that can read that, unless the motherboard can if one of the pins in the CPU socket is a sensor that measures that. TJ Max is Temp Junction, the temp of the indivdual cores, which is normally much higher than Tcase. Software such as Core Temp and Real Temp can interpret that. Notice I say interpret, as the numbers are usually close but not exact. That's why I agree with Paul. I would never go close to the max. But, Ivy Bridge creates a lot of heat while running stress tests, but it is also pretty tough and can take the heat.

 

[Britton30]

Here is a definition from Intel. TCase is the temp measured in the IHS (Integrated Heat Spreader)
Processors — Processor operation temperature FAQ

 

[Dude]

Thank you for the responses

 

[Britton30]

You're welcome, now you can be as confused as me.

 

[mjf]

Now I find this interesting from the Intel reference:
"TCASE is the temperature measurement using a thermocouple embedded in the center of the heat spreader. This initial measurement is done at the factory. Post-manufacturing, TCASE is is calibrated by the BIOS, through a reading delivered by a diode between and below the cores."

I wasn't aware that in production chips that this sensor was implanted.

I thought that it was the DTS sensor that was available in production units.

"Tjunction is synonymous with core temperatures, and calculated based on the output from the Digital Thermal Sensor (DTS) using the formula Tjunction = (Tjunction Max – DTS output)."

Yours,
slightly confused

 

[Golden]

I've edited the tutorial and replaced TCase with Maximum Operating Temperature, to avoid confusion.

 

[essenbe]

Mjf, I have read on the Core Temp forum that the DTS actually does not tell the temp, it tells the distance to TJ Max. I think that makes your last sentence make sense.

 

[Britton30]

Michael, there isn't a thermocouple embedded in the IHS, but that is where Tcase would be read. As Steve said, the temps we see are calculations made by the software based on the DTS outputs.

 

[mjf]

Michael, there isn't a thermocouple embedded in the IHS, but that is where Tcase would be read. As Steve said, the temps we see are calculations made by the software based on the DTS outputs.

That has been my understanding and it can cause a lot of confusion. What I don't understand is why Intel don't spec their devices based on DTS outputs. Why give a spec (eg. Tcase) if you can't accurately measure it?

 

[Dude]

This turned into an interesting conversation. I'm confused as much now as when I started it, but I understand it now. Just don't ask me to explain it.

 

[paulpicks21]

This turned into an interesting conversation. I'm confused as much now as when I started it, but I understand it now. Just don't ask me to explain it.

My brain just exploded Dude:roflmao:

 

[Britton30]

This turned into an interesting conversation. I'm confused as much now as when I started it, but I understand it now. Just don't ask me to explain it.

My brain just exploded Dude:roflmao:

Now you know as much as the rest of us.

 

[essenbe]

I read a post by the author of Core temp. He explained a bunch of that and the fact that neither Intel nor AMD will give any info on what the readings of the DTS actually mean. They have to try to figure it out. I always thought that the DTS told how far you were from TJMax, so if you know what TJ Max is and how far you are from it, you can come pretty close to actual temp. But, maybe not.

I guess, if one of the 1155 pins in my CPU socket read the T Case, the motherboard would know. I read on the ROG forums that the AI Suite read Tcase. It either does or is way way off. It can give temps 20 - 30° lower than core temp, real temp or any other program.

Why Intel or AMD won't release that info is beyond me.

 

[Britton30]

Right Steve, why is a temperature reading treated like some state secret?

 

[essenbe]

Gary, I'm sure you know I cannot answer that. If I even knew the answer I would probably be executed at sunrise.

 

[Layback Bear]

Something I found.

Guide to Understanding Intel Temperatures | TechREACTION

 

[Lady Fitzgerald]

Something I found.

Guide to Understanding Intel Temperatures | TechREACTION

Good reading. Thanks for that!