Intel to disclose the maximum Tjunction values for 45nm Core 2s

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BillParrish

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IDF (Intel Developer Forum) 2008 news. IDF is scheduled this year for August 19 - 21 in San Francisco.

Will disclose


first-ever public disclosure of the maximum Tjunction value for all Core 2 Duo/Quad/Extreme desktop processors built on current 45nm-process technology.

by Intel.

http://www.anandtech.com/weblog/showpost.aspx?i=478




I predict it will not have any effect on the 100,000 totally redundant "How are my temps", "Am I too hot" posts but perhaps in 4 months the ever popular "Which program has the correct temp" may drop in volume. /cheer !!!
 
They've contacted me about this and have let me know that they'll be using RealTemp in their presentation. Hopefully that means that RT has been getting more of the 45nm processors right than wrong!
 
Unlikely to have any effect on the threads, no, because the fact that it's not about to hit Tjunction max doesn't mean that it's not "too hot".
 
unclewebb said:
They've contacted me about this and have let me know that they'll be using RealTemp in their presentation. Hopefully that means that RT has been getting more of the 45nm processors right than wrong!
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Nice job - are they going to pay you royalties since they are using it for commercial purposes?
 
Forceman said:
Nice job - are they going to pay you royalties since they are using it for commercial purposes?
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I won't hold my breath waiting for a royalty check. :)

It will be interesting what they have to say and how much they have to say. The truth can sometimes get filtered a little when it has to go by the lawyers first. The press release only mentions 45nm but I hope they also speak about the previous 65nm sensors because they weren't perfect either.
 
About time. I wonder though why it's taken them so long to come out with this info.
 
Zero82z said:
About time. I wonder though why it's taken them so long to come out with this info.
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My guess it was the hit in the pocketbook. After enough people probably called support about "heat" problems (real or not) which of course costs money, they decided it is not worth it to keep TJMax a secret. Other than conserving money, I don't see of another reason why Intel would care. Standard corporate mentality is easy to figure out.
 
Mithent said:
Unlikely to have any effect on the threads, no, because the fact that it's not about to hit Tjunction max doesn't mean that it's not "too hot".
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I disagree, one of the issues is that most people think the badly named TjMax is the maximum temp the CPU can handle. Not true. "TjMax" is the point where the CPU sends out the PROCHOT# interrupt telling the thermal solution to spin the fans up to 100%. Per Intel's spec and warranty you can run at 1 deg C delta to Tj(Max) (I really want to say AT TjMax but its somewhat ambiguous per the specs) 24x7x3 years and Intel will honor the warranty. Now to most of us that is indeed "too hot" and we would not do it. However my point remains. There is a second higher temp, the "catastrophic temp trip" where the CPU (or MCH if you are interested) will shutdown to save itself. Now that is most definitely "too hot". :D So its a matter of mincing words about what "too hot" means to each person. I take the technical/engineering side in stating absolute facts, when I have them, but must admit I would never let my cpu get within 10C of "TjMax". But since Intel will warranty proper operation up to and at TjMax I find it difficult to point to that as a source of failure when people post. What would be interesting is someone doing a max cpu frequency vs temp to see how OCing in conjunction with high temps effects cpu stability.

They've contacted me about this and have let me know that they'll be using RealTemp in their presentation. Hopefully that means that RT has been getting more of the 45nm processors right than wrong!
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Gratz uncleweb !!!! I remember your post where you pulled the HS off and tested for TjMax with the IR thermo. A classic [H]ard as they come effort.
 
Great when they're getting ready to move on to Nehalem, they finally talk about Core 2. Too little too late IMHO.

At this rate, maybe in 2+ years, they'll grace us with the information for Core i7 (Nehalem) when they're getting ready to come out with the next gen chips.
 
I'm guessing they are releasing the tjunction values, due too many people returning their 45nm processors due to temp issues.
 
Shadowthor said:
I'm guessing they are releasing the tjunction values, due too many people returning their 45nm processors due to temp issues.
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? my E7200 Idles at 28C, and i haven't heard of people having problems with quads either. Besides, sombody smart enough to monitor their system temp is smart enought to know how to cool it down
 
Thanks BillParrish. I've been testing / torturing these chips for a long time now. Still haven't had one fail which says a lot about quality.

I have done some high temperature running of Prime and tested for stability when overclocked. Not surprisingly, the more you overclock, the cooler you have to run your processor to guarantee long term Prime stability. When pushing my Q6600 or E8400 hard, they can both easily run Prime when overclocked by 20% up to the thermal throttling point at just before 95C. During testing, throttling typically begins at 2 degrees before TjMax which gives a processor a chance to cool down so it can continue to run without actually hitting TjMax. Thermal shut down seems to be at 125C but it's not officially documented for the desktop processors.

When you overclock beyond 20%, it's time to start dropping the core temperature. At 4050 MHz, my E8400 quickly loses long term Prime stability in the low 60C range even though at 3600 MHz, it can happily run at 90C to 95C.

These CPUs run so good that TjMax really isn't that important but it will give everyone something new to talk about. I just hope that the Intel disclosure is clear and thorough and that all software developers can use the same formulas to convert data from these chips into some meaningful and comparable temperature numbers. Never hurts to dream!

The latest beta version of RealTemp is ready for download from the beta section. I'm not allowed to post a link to that so you'll have to rely on your friend Google to hunt it down. It has user adjustable colors now. I thought RT might need a tux and tie for the IDF conference. :D

rt273jf6.png


Edit: A double left mouse click will take you to Mini Mode.
 
My Real Temp and CoreTemp/Hardware Mon/Speedfan/Nforce tools etc etc, all say a vastly different amount. Real Temp is the only one that's different.
 
Hopefully we'll find out in a couple of more days after Intel fully discloses everything there is to know about these sensors. Software writers have been left guessing with no documentation provided by Intel. At least the numbers behind RealTemp are based on some real world testing with an IR thermometer. Send an e-mail to the address in the About box of RealTemp and I'll be happy to send you links to some of the testing I've done. Unfortunately I've had my ability to post links turned off so I can't post that here.
 
Valnar said:
My guess it was the hit in the pocketbook. After enough people probably called support about "heat" problems (real or not) which of course costs money, they decided it is not worth it to keep TJMax a secret. Other than conserving money, I don't see of another reason why Intel would care. Standard corporate mentality is easy to figure out.
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Well, what I meant was that I wonder why Intel didn't just release this info earlier. I don't see how it could harm them at all, so I'd be curious as to the reasoning behind keeping this secret from people.
 
soo umm any one know whats up and why there isnt any news about this yet? Anandtech said to day ; ;
 
Here's the summary. Only 45nm processors not 65nm.

Desktop TJ For Dual and Quad Core CPUs
45nm Desktop Dual-Core Processors TJ
• Intel® Core™2 Duo processor E8000 and E7000 series 100°C

45 nm Desktop Quad-Core Processors
• Intel® Core™2 Quad processor Q9000 and Q8000 series 100°C
• Intel® Core™2 Extreme processor QX9650 95°C
• Intel® Core™2 Extreme processor QX9770 85°C
 
msabo said:
Here's the summary. Only 45nm processors not 65nm.

Desktop TJ For Dual and Quad Core CPUs
45nm Desktop Dual-Core Processors TJ
• Intel® Core™2 Duo processor E8000 and E7000 series 100°C

45 nm Desktop Quad-Core Processors
• Intel® Core™2 Quad processor Q9000 and Q8000 series 100°C
• Intel® Core™2 Extreme processor QX9650 95°C
• Intel® Core™2 Extreme processor QX9770 85°C
Click to expand...

Doesn't Realtemp use 90C? And Coretemp 100?

So Coretemp was right all along?

Or is it 95 and 105 and they split the difference - I'm not at home to check right now.
 
Forceman said:
Doesn't Realtemp use 90C? And Coretemp 100?

So Coretemp was right all along?

Or is it 95 and 105 and they split the difference - I'm not at home to check right now.
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Real Temp was 95 for my Q9450, I guess I'll be nudging it up to 100.
 
I had reltemp set to 105C for my E8500! I also had to use -5 C offset with Speedfan 4.35 final. The E8500 is even cooler chip than I thought.:D
 
so the question is now with the 7000 and 8000's is

this is just the fan throttle up point right?
so do that mean 80 to 90 C is totally fine to be running at?
 
Elios said:
so the question is now with the 7000 and 8000's is

this is just the fan throttle up point right?
so do that mean 80 to 90 C is totally fine to be running at?
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Actually, the official TJmax value will enable calculation of core temp correctly.
 
Actually, the official TJmax value will enable calculation of core temp correctly.
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Actually it does not.

Carefully read slide 7 ( Sensor Calibration) and think about what it is saying in regards to picking a Tj for your monitoring software. Hint, its the bit about "Each device is individually calibrated" so if you want you can grab the numbers from the slide 13 and run away all happy and everything will be fine, but you still dont understand what is really going on. Delta to Tjuncion is still the only really meaningfull number until Nehalem. Why do I say that ? Read on.

This is interesting, Nehalem will have a software register were we can read the factory calibrated temp where PROCHOT is asserted (typically called Tj Max). From slide 14:

Software visible register contains the target TJ
–A new feature in the Intel®Core™i7 processor is a software readable field in the IA32_TEMPERATURE_TARGET register that contains the minimum temperature at which PROCHOT# will be asserted. The PROCHOT# activation temperature is calibrated on a part-by-part basis and normal factory variation may result in the actual activation temperature being higher than the value listedin the register. PROCHOT# activation temperatures may change based on processor stepping, frequency or manufacturing efficiencies.


"Note again that this value (like slide 7) is adjusted on a part by part basis for each individual chip and thus any one generic Tjmax value, while being close enough, is still not the actual value to use. But on Nehalem at least we can see what they put in at the factory. (Keeping in mind that all Tjmax means it that the CPU thinks its hot and signals the fans to speed up 100%.

It would have been very interesting if they had given values on the true Tj catastropic trip point at which temp the cpu will shutdown.

Franly little new here on existing CPUs other than to throw out some target numbers for the 45nm chips that by their own data/slides are not absolute values anyway due to factory calibration. eh. its something and will make a lot people happy, I am not impressed of a rehash of info found in old Intel tech journals and datasheets. The Nehalem tidbit is the real nugget and UncleWebb gets to rewite his excellent software yet again once they tell us the register address. :eek:
 
Actually slide 8 is of far bigger concern to me. It says, “Slope error overshadows calibration error at lower temperatures”. This basically means that in the normal operating range, the DTS is simply not accurate!!! So what it’s saying loud and clear is, Don’t use DTS data to calculate temperature! DTS should be used for fan speed control & thermal solution failure detection only.

Just look at the “slope induced error” in your normal operating range on the graph. The slope induced error issue dominates this problem space. Screw it, I’m sticking with Tcase.
 
there is still the question of what is a "safe" value to run at under full load
if the Tj is just when the CPU sends the PROCHOT#
then is any value under it ok to run at?

and 100c seems really high to me to just be were your throttling up the fan imo
i really would never like to see a CPU get over 70c and 80c as top end limit with 100c maybe being the CPU throttle back temp
 
Elios said:
there is still the question of what is a "safe" value to run at under full load
if the Tj is just when the CPU sends the PROCHOT#
then is any value under it ok to run at?

and 100c seems really high to me to just be were your throttling up the fan imo
i really would never like to see a CPU get over 70c and 80c as top end limit with 100c maybe being the CPU throttle back temp
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I suggest you use the thermal spec for your processor if you are looking at "safe" operating temperatures. My Q9450 has a thermal spec of 71.4°C, as measured by Tcase. So I keep it under 65C, to allow for Tcase inaccuracies. And to BillParrish point, you might also keep an eye on Delta to Tjuncion if you are doing some serious stress testing.
 
The 71.4°C refers to the Tcase temperature at maximum TDP. Delta to tjunction max gives you the amount of headroom you have till the onboard safety features determine the processor to be "too warm" and starts measures to reign it back in before shutting off.
 
msabo said:
I suggest you use the thermal spec for your processor if you are looking at "safe" operating temperatures. My Q9450 has a thermal spec of 71.4°C, as measured by Tcase. So I keep it under 65C, to allow for Tcase inaccuracies. And to BillParrish point, you might also keep an eye on Delta to Tjuncion if you are doing some serious stress testing.
Click to expand...

so lets say that my CPU is the same 71.5C
how do you read the Tcase if the only way to get a temp out of the CPU is from the Tjmax delta?
 
msabo said:
Tcase is a seperate sensor.
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No, it's not. It is the temperature measured at the top center of the heatspreader. There is no way to measure it directly without modding your chip, which is why everyone uses Tj.
 
msabo said:
Actually slide 8 is of far bigger concern to me. It says, “Slope error overshadows calibration error at lower temperatures”. This basically means that in the normal operating range, the DTS is simply not accurate!!! So what it’s saying loud and clear is, Don’t use DTS data to calculate temperature! DTS should be used for fan speed control & thermal solution failure detection only.

Just look at the “slope induced error” in your normal operating range on the graph. The slope induced error issue dominates this problem space. Screw it, I’m sticking with Tcase.
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I agree. I have a slightly different view of what the impact is but do not disagree with you at all. To me, notice how the error gets smaller as you approach Tj (god I wish they would start calling that Tprochot). The major thing I get out of it is that using the DTS to determine/say/brag/whatever your idle temps are is pure shite. How much shite Intel does not bother to tell us. Probably at least a couple of degs of shite.

Still, dont get me wrong, DTS regarless of its shortcomings is a hella lot better than using artic adhesive and glueing a thermistor to the side of the IHS. I am just not happy unless I got something to bitch about :D
 
Forceman said:
No, it's not. It is the temperature measured at the top center of the heatspreader. There is no way to measure it directly without modding your chip, which is why everyone uses Tj.
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Where did you get that idea? All Core 2 Quad and Core 2 Duo processors have two different types of temperature sensors. One is a CPU case thermal diode which is located within the CPU die between the cores. The case thermal diode is used to measure the temperature of the CPU case (Tcase). Tcase is what utilities, such as Everest, report as the CPU temperature. You don't need to mod your chip to get Tcase.

The second temperature sensors are the Digital Thermal Sensors (DTS) located within each Core. The DTS measures distance to PROCHOT activation. Utilities such as Real Temp and Core Temp attempt to use DTS to derive core temperatures.
 
msabo said:
Where did you get that idea? All Core 2 Quad and Core 2 Duo processors have two different types of temperature sensors. One is a CPU case thermal diode which is located within the CPU die between the cores. The case thermal diode is used to measure the temperature of the CPU case (Tcase). Tcase is what utilities, such as Everest, report as the CPU temperature. You don't need to mod your chip to get Tcase.

The second temperature sensors are the Digital Thermal Sensors (DTS) located within each Core. The DTS measures distance to PROCHOT activation. Utilities such as Real Temp and Core Temp attempt to use DTS to derive core temperatures.
Click to expand...

That is completely wrong. There is only one sensor on a processor, and that is the DTS located inside the core itself. The temperature Intel refers to as Tcase is measured external to the processor on the top center of the integrated heat spreader. I'd find the Intel reference document that specifies this, but that would require searching, when I'm quite sure that BillParrish can quote that baby out by heart, given all the times he's done it on these forums. The temp reported as CPU temp by Everest, et al, is probably a sensor located somewhere on the motherboard. But there is unquestionably only one sensor on the CPU chip itself.

Okay, I postponed lunch for a minute to locate this - it is specifically about the E7500 but the section that matters is in all of them.

http://www.intel.com/Assets/PDF/designguide/E7501-298647.pdf

Read Section 5 of this document, it is pretty clear about how to measure Tcase. I'll quote the relevant parts:

"To ensure functionality and reliability, the Tcase of the MCH must be maintained at or below the maximum temperature specifications as noted in Table 1 and Table 2. The surface temperature at the geometric center of the die corresponds to Tcase. Measuring Tcase requires special care to ensure an accurate temperature measurement."

It then lays out procedures for placing the thermocouple to measure this, which involves, according to their procedures, milling a hole in the heatsink.
 
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