So on a Q6600 G0, if Intel says Thermal Specification is 71C...

N

nerr

Limp Gawd
Joined
Jun 19, 2008
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Does that mean that 71C is pretty much the absolute max you'll want to hit before temperatures get dangerous? I'm running at about 63C on Prime95 right now, stress testing at 3.6 GHz after properly reapplying thermal paste. I've noticed sometimes temperatures in Prime95 will spike if it starts to work on some very large FFTs. As long as I stay below 71C, I'm perfectly fine, correct?

I apologize for sounding sort of n00bish... but well, I've never been able to take my Q6600 quite this far before, and I just want to make sure I'm still okay. Thanks!
 
71°C is the temperature at maximum TDP measured via a diode placed into the IHS. Read the white paper again.
 
Instead of being an elitest, why not simply tell him in layman's terms. The poor guy just wants to know if he's going to be ok.
 
Well I assumed that he read the paper since he said that Intel said that.

If you don't want to know anything behind the whole temperature and processors thing, then skip to the bottom.

TDP = thermal design power, amount of power the processor will "put out" that the heatsink will be required to dissipate.

The figure is given in watts, but it is also the worst case scenario number at stock speeds (which I guess we can throw out in this situation).

The IHS is the integrated heat spreader, or the casing on the processor over the cores. The silver thing with the model number, assembly location, and other little details is the IHS.

The white papers for the quads give details as to the methodology for taking these temperature readings.

What you should keep an eye out for is the Tjunction Max, which is when the processor begin to throttle itself because it think it's too hot. The white papers will also explain how this "Thermal monitor" work and what "PROCHOT#". I can paraphrase:
According to Intel's documentation, this temperature value (71°C) is measured at the Tcase for the amount of heat being dissipated (95w).
Page 71:
Intel said:
To allow for the optimal operation and long-term reliability of Intel processor-based systems, the system/processor thermal solution should be designed such that the processor remains within the minimum and maximum case temperature (TC) specifications when operating at or below the Thermal Design Power (TDP) value listed per frequency in Table 26.
Click to expand...
Pages 73 through 75 contain tables and charts comparing temperature of the Tcase when the processor is dissipating the specified amount of heat. What is Tcase? This PDF refers us to another datasheet found here:
http://www.intel.com/design/processor/designex/315594.htm
Page 18, Section 2.2.1:
Intel said:
For the processor, the case temperature is defined as the temperature measured at the geometric center of the package on the surface of the IHS.
Click to expand...
Appendix D describes the Tcase measurement methodology, which involves cutting a groove on the IHS (Integrated Heat Spreader).

Next, with regards to what's "too hot" and "will my chips die?" this is what I've found.

From the thermal and mechanical datasheet I linked earlier:
Page 33, Section 4.2:
Intel said:
The Thermal Monitor consists of the following components:
• A highly accurate on-die temperature sensing circuit.
• A bi-directional signal (PROCHOT#) that indicates if the processor has exceeded its maximum temperature or can be asserted externally to activate the Thermal Control Circuit (TCC) (see Section 4.2.1 for more details on user activation of TCC via PROCHOT# signal).
• FORCEPR# signal that will activate the TCC.
• A Thermal Control Circuit that will attempt to reduce processor temperature by rapidly reducing power consumption when the on-die temperature sensor indicates that it has exceeded the maximum operating point.
• Registers to determine the processor thermal status.
Click to expand...

So PROCHOT# will trip when the processor has reached an unspecified temperature.
Page 34, Section 4.2.1:
Intel said:
The temperature at which the PROCHOT# signal goes active is individually calibrated during manufacturing. Once configured, the processor temperature at which the PROCHOT# signal is asserted is not re-configurable.
Click to expand...
So while we have some numbers that are generally accepted, we can't be sure.
Anyway, once PROCHOT# has been tripped, it activates TCC or Thermal Control Circuit, which has two methods of reducing power dissipation (page 34 or section 4.2.2). Thermal Monitor 1 and Thermal Monitor 2. Both involve throttling the processor frequency. If this doesn't work..
Page 38, Section 4.2.7:
Intel said:
In the event of a catastrophic cooling failure, the processor will automatically shut down when the silicon temperature has exceeded the TCC activation temperature by approximately 20 to 25 °C. At this point the system bus signal THERMTRIP# goes active and power must be removed from the processor. THERMTRIP# activation is independent of processor activity and does not generate any bus cycles. Refer to the processor datasheet for more information about THERMTRIP#. The temperature where the THERMTRIP# signal goes active is individually calibrated during manufacturing and once configure can not be changed.
Click to expand...

Tjunction max for 65nm chips (or the Q6600) is 100°C.

Is it too hot? No, it's far from it. 63°C at 3.6 GHz with all four cores loaded is safe.
 
Googling for this brings up all kinds of old topics and speculation, do you have a link saved somewhere?

Oh and nevermind, OP didn't have to have read the white paper to get the Thermal Specification number. It's on the spec sheet:
http://processorfinder.intel.com/details.aspx?sSpec=SLACR#

However, s/he could've clicked to find the definition of the Thermal Specification.
 
Well thank you very much gwai lo for the detailed explanation. You taught me a few things, which is great!

But wow, 90C is where it gets dangerous? Oh wow. So I should be good to go for quite a while yet. I'm currently stable for about 2 hours time at full load under Prime95... so we'll see where this goes. Max temperature has only been 66C so far. Hmm... so if I really wanted to push it, I could up the voltage to ~1.45 V instead of 1.40V and potentially shoot for 3.7 or 3.8? Interesting. Once I find a place where I can get 3.6GHz stable, that might be my next mission... after I add a few case fans, and zip tie another to my heatsink.
 
nerr said:
Well thank you very much gwai lo for the detailed explanation. You taught me a few things, which is great!

But wow, 90C is where it gets dangerous? Oh wow. So I should be good to go for quite a while yet. I'm currently stable for about 2 hours time at full load under Prime95... so we'll see where this goes. Max temperature has only been 66C so far. Hmm... so if I really wanted to push it, I could up the voltage to ~1.45 V instead of 1.40V and potentially shoot for 3.7 or 3.8? Interesting. Once I find a place where I can get 3.6GHz stable, that might be my next mission... after I add a few case fans, and zip tie another to my heatsink.
Click to expand...

TjMax is the "do not go over" temp. Have you tried running IBT and seeing what your temps are? What kind of cooler are you using? I like staying about 20C under TjMax, some people are fine with just 10C under, as the chances of hitting the temps you do with the likes of IBT are slim, but temps in my house vary pretty wildly depending on my mood.

But try IBT (I do about 20-25 passes) it will save you allot of time from having to run Prime for hours on end.
 
Edit: IBT = Intel Burn Test? I'll download it right now and test.

I'm running a Xigmatek HDT-S1283 with backplate retention bracket. Temps currently reported after 2 hours, 10 minutes of Large FFT test in Prime95 are 69/69/62/62.

Edit 2: WOW! I just ran Intel Burn Test for about ten seconds before my RAM maxed out and my system shut down. I had set it to shut down once the processor hit 75C, so I guess it exceeded that limit. I'm now at my BIOS' default setting of 85C. Holy crap. This is crazy... I'll try once more.
 
100c is the limit on the chip before it'll shut itself off. It starts throttling at 98c I believe I read somewhere. 70c is perfectly acceptable as long as it's stable. Some people are anal and don't like to go over 65c or 60c, but it really won't make a difference.
 
WOW! I am not messing with Intel Burn Test. My system failed after about 85C... I know that's for the real hardcore, but the most intensive task I'll ever do is a 24-28 hour 1080p H.264 encode. I'm just going to run Prime95 overnight, and if it can run for 8+ hours, then so be it.
 
nerr said:
WOW! I am not messing with Intel Burn Test. My system failed after about 85C... I know that's for the real hardcore, but the most intensive task I'll ever do is a 24-28 hour 1080p H.264 encode. I'm just going to run Prime95 overnight, and if it can run for 8+ hours, then so be it.
Click to expand...

Haha, it's showing that there is instability in the OC. Is it shutting down because of the temp or is it BSODing? I use IBT all the time, before I used it I had a "stable" system on my 3GHz OC on my old E2180 using prime, was fine for weeks, and then BSODed on me in the middle of a rather large, but thankfully rather simple (and mostly saved) file. I heard about IBT used it and it crashed before load even hit 100%, since I have used it I have not had any problems like that again. But it's your OC, if your happy with just prime so be it.
 
nerr said:
Edit: IBT = Intel Burn Test? I'll download it right now and test.

I'm running a Xigmatek HDT-S1283 with backplate retention bracket. Temps currently reported after 2 hours, 10 minutes of Large FFT test in Prime95 are 69/69/62/62.

Edit 2: WOW! I just ran Intel Burn Test for about ten seconds before my RAM maxed out and my system shut down. I had set it to shut down once the processor hit 75C, so I guess it exceeded that limit. I'm now at my BIOS' default setting of 85C. Holy crap. This is crazy... I'll try once more.
Click to expand...

lol, be careful with that IBT. You better have a really good heatsink thats packing some major cfm fans to dissipate that power as quickly as possible. My Q6600 @ 3.88 (1.54 vdrop) rarely goes above 70C in IBT but thats with the Xig XHT-S1284EE + Scythe Slipstream 110Cfm and Scythe Ultra Kaze 133Cfm fan. Also with the case in sig open, these stock fans just really suck at generating any airflow.
 
The closer you run that cpu to TJ Max, I'm pretty sure the shorter it's life. Any descent heat sink like
a TRUE or tuniq tower should be able to handle 3.6 on a Q6600 without going over 65c in games.
 
MocciBoo said:
The closer you run that cpu to TJ Max, I'm pretty sure the shorter it's life. Any descent heat sink like
a TRUE or tuniq tower should be able to handle 3.6 on a Q6600 without going over 65c in games.
Click to expand...

You "might" shave 2-3 years off of it's 10-20year life. I'd say keep it under 80c. I've seen my share of OEM (HP/Dell) SFF Q6600 systems idle in the 50's and load in the 80's at stock speed. By the time you kill it with heat(fire..lol) the chip will have surpassed it usefullness anyways.
 
My q6600 rarely ventures much over 70'c at 100%load, even when gaming it never goes much over 50'c examples of some of my overclocks.

3.8ghz
untitled-2.jpg

3.6ghz
untitled-1.jpg
 
Hmm... I'm still loading near about 66-70C in Prime95. I was able to stress test last night for about six hours before failure, so I upped the FSB, NB, and CPU voltages slightly to see where that will take me.

I could really use a few extra fans though, I'm starting to think. At least one more on the other side of my CPU cooler to pull air from it and work complementary to the fan mounted to push air into it. Recommendations on a nice fan? It'll just need to be something I can zip-tie to the back of my cooler. Doesn't necessarily have to be pretty!
 
MocciBoo said:
The closer you run that cpu to TJ Max, I'm pretty sure the shorter it's life. Any descent heat sink like
a TRUE or tuniq tower should be able to handle 3.6 on a Q6600 without going over 65c in games.
Click to expand...

Voltage will have a far larger impact on life than temps, unless you are running REALLY hot 24/7.
 
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