What is the TJ MAX for the Q6600 G0?

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LOUISSSSS

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Dec 5, 2005
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the new version of Real Temp allows custom settings for TJ MAX. Ver 2.70. i am wondering what the latest listing for the TJ MAX by Intel was for the Q6600 G0 stepping? thanks.

PS what are u guys using to monitor temps for the Q6600?
 
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clarkey01

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Feb 4, 2004
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Originally posted by: LOUISSSSS
the new version of Real Temp allows custom settings for TJ MAX. Ver 2.70. i am wondering what the latest listing for the TJ MAX by Intel was for the Q6600 G0 stepping? thanks.

PS what are u guys using to monitor temps for the Q6600?
Click to expand...

Would the new version of real temps be accurate for reading the temps for a Q6600? I thought real temps was ment for 45nm CPU's?
 
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LOUISSSSS

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Dec 5, 2005
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it actually doesn't matter between 45nm and 65nm because with the 2.70 version of realtemp, you can manually set TJ MAX so it should work for both, as long as u KNOW the TJ MAX for your CPU. mine is the Q6600 (G0, 65nm)
 
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wwswimming

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rge

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There is a relationship between Tcase and tjmax...here is a post I made on xtreme after tjmax on 45nm was released to use that now known relationship of 45nm for 65nm. We know casing temp of Q6600 is 95C when DTS=0 (tjmax reached), so must be 95C or higher. Casing temp on E8400 is 95C when DTS=0 and tjmax is 100C (per intel) so assuming 5C gradient for most at idle undervolted, underclocked where measurements are made....Q6600 GO is presumed 100C.

http://www.xtremesystems.org/f...3243922&postcount=2152
 
ViRGE

ViRGE

Elite Member, Moderator Emeritus
Oct 9, 1999
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Holy cow, good find.:Q

All this time I thought my Q6600 B3 was running hot when it maxed out at 70C; with an 80C TJMax, it really was only at 50C.:Q
 
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Tempered81

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Jan 29, 2007
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gives e8400's tons more headroom because people had their early e6400s and q6600s in the 60's, that's like having an e8400 in the 80's.
 
Liet

Liet

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Jun 9, 2001
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Would someone mind explaining this to a noob like myself?

Does this mean I should be able to safely run my Q6600 at 60-65c without really bringing down the life expectancy?
 
Liet

Liet

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Jun 9, 2001
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Thanks kindly... I have a G0, so if I input the TJMax of 90c into a program like Realtemp I'll get an accurate reading, yes? Currently I'm using Speedfan and showing 55c at full load, and I'm worried that's not accurate.

 
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Tempered81

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Jan 29, 2007
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we did some testing (well rge did all the actual testing, drilling holes into his e8400's.) he placed a thermocouple inside the IHS ontop of the cpu to get a digital temperature of the IHS while he stressed the cpu.

We tried to compare his results to intel's e8400 specs:

sSpec Number:SLAPL
CPU Speed:3 GHz
PCG:06
Bus Speed:1333 MHz
Bus/Core Ratio:9
L2 Cache Size:6 MB
L2 Cache Speed:3 GHz
Package Type:LGA775
Manufacturing Technology:45 nm
Core Stepping:C0
CPUID String:10676h
Thermal Design Power:65W
Thermal Specification:72.4°C
VID Voltage Range:0.85V ? 1.3625V


sSpec Number:SLB9J
CPU Speed:3 GHz
PCG:06
Bus Speed:1333 MHz
Bus/Core Ratio:9
L2 Cache Size:6 MB
L2 Cache Speed:3 GHz
Package Type:LGA775
Manufacturing Technology:45 nm
Core Stepping:E0
CPUID String:1067Ah
Thermal Design Power:65W
Thermal Specification:74.1°C
VID Voltage Range:0.85V ? 1.3625V

specifically the numbers 74.1C & 72.4C are supposed to be the maximums of what his thermocouple was measuring. He saw an actual tcase temp of 57C on this (where intel says limit is ~73C) when the core temperatures were reading 84C. This supports the fact that virutalLarry has been running his core2duos at 91C load for a long time with no heat-related cpu damage. He was never actually reaching the Tcase max (intel thermal specification) for his chip.

This could mean that when people see temps of 75C and get worried, they are actually nowhere close to having a Tcase of 75C, in fact Tcase is more likely closer to 55C - 60C at that point. We will wait for rge to conduct more testing to get some conclusive results. right now it looks promising. IMO what this boils down to is "don't be afraid of higher temps" (within your TJmaximum).

Intel's Thermal Spec:
http://processorfinder.intel.c...aspx?label=ThermalSpec
"The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader. For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor Intel® Thermal Monitor. The Intel Thermal Monitor?s automatic mode is used to indicate that the maximum TJ has been reached."

rge's testing:
http://www.xtremesystems.org/f...?p=3381128#post3381128


 
VirtualLarry

VirtualLarry

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Aug 25, 2001
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Originally posted by: jaredpace
specifically the numbers 74.1C & 72.4C are supposed to be the maximums of what his thermocouple was measuring. He saw an actual tcase temp of 57C on this (where intel says limit is ~73C) when the core temperatures were reading 84C. This supports the fact that virutalLarry has been running his core2duos at 91C load for a long time with no heat-related cpu damage. He was never actually reaching the Tcase max (intel thermal specification) for his chip.

This could mean that when people see temps of 75C and get worried, they are actually nowhere close to having a Tcase of 75C, in fact Tcase is more likely closer to 55C - 60C at that point. We will wait for rge to conduct more testing to get some conclusive results. right now it looks promising. IMO what this boils down to is "don't be afraid of higher temps" (within your TJmaximum).
Click to expand...

Sounds good. One thing to consider, is with the revised TJmax numbers (none given in those charts for the E2xxx series, did Intel forget about them?), I wasn't loading at 91C after all. Assuming that the TJmax for E2xxx M0 is same as E4xxxx (80C), then 9C away from TJmax is only 71C. So I guess I'm not torturing those chips as much as I thought.
 
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Tempered81

Diamond Member
Jan 29, 2007
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yah not too sure about how intel calculates it because, for example: An e6750 G0 stepping has a Tjmax of 80C and a Thermal Specification of 72C. That leaves only 8C for gradient at maximum temp if our E8400 theory is correct and true between wolfdale & conroe.

Oh well, Rge, what is your opinion on this one!? :p

 
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rge

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Feb 18, 2008
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Originally posted by: jaredpace
yah not too sure about how intel calculates it because, for example: An e6750 G0 stepping has a Tjmax of 80C and a Thermal Specification of 72C. That leaves only 8C for gradient at maximum temp if our E8400 theory is correct and true between wolfdale & conroe.

Oh well, Rge, what is your opinion on this one!? :p
Click to expand...

Intel has stated that most cpus (probably all 65nm) have significantly raised DTS offsets to prevent throttling below tcase, per presentation at IDF, see slides 7 and 13. The chart on slide if drawn to scale could easily represent 15-20C offsets.


Intel has stated the formula for calculating temps is
diplayed temp = tj target-DTS + DTS offset

For E8400, DTS offset = 0 as measured by IR, so temp = Tj target -DTS

For E6850 or E6750 GO, DTS offset = ~20C (constant) measured by IR (Tcase is 95C on E6850 GO when DTS=0)
displayed temp = tj target (80) - DTS + 20C offset
same thing as using tj 100(effective after adding offset) - DTS

Intel clearly states this in IDF presentation, clearly showed charts with large offsets drawn, but did not give offset numbers. But they can be easily approximated with reading tcase measurements at DTS=0. Unless intel can provide offsets, that is what we are left with. But if I use 80C for my E6850 GO tjuntion than at 80C core my IHS is 95C...I would be defying the laws of physics.

What is interesting is if you use the numbers intel gave you for 65nm without offsets when you are running certain loads like linpack core temps that are displayed will approximate actual Tcase (IHS) readings but at idle you will likely see nonsensical temps displayed... ie near or below 0C.
 
VirtualLarry

VirtualLarry

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Aug 25, 2001
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Originally posted by: rge
Intel has stated that most cpus (probably all 65nm) have significantly raised DTS offsets to prevent throttling below tcase, per presentation at IDF, see slides 7 and 13. The chart on slide if drawn to scale could easily represent 15-20C offsets.


Intel has stated the formula for calculating temps is
diplayed temp = tj target-DTS + DTS offset

For E8400, DTS offset = 0 as measured by IR, so temp = Tj target -DTS

For E6850 or E6750 GO, DTS offset = ~20C (constant) measured by IR (Tcase is 95C on E6850 GO when DTS=0)
displayed temp = tj target (80) - DTS + 20C offset
same thing as using tj 100(effective after adding offset) - DTS

Intel clearly states this in IDF presentation, clearly showed charts with large offsets drawn, but did not give offset numbers. But they can be easily approximated with reading tcase measurements at DTS=0.
Click to expand...

How... confusing. So, just knowing TJmax for a given CPU is in fact no enough, now we have to find out these "offsets", which essentially raise "effective" TJmax, so perhaps the effective TJmax of my E2xxx is in fact really still 100C? So my load temps really are 91C?
 
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rge

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Feb 18, 2008
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yep...and what is worse, the calibration like intel states vary part to part, so possibly so do the offsets, which is maybe why they were not provided. But since several have tested same cpus and get the same "offsets", you are better using current tjunction than changing. Both real temp and core temp authors have said they are not using the tjunction targets for 65nm...until can find the offsets or measured them in real temp case. Also intel changed term to tj target, probably because it is not tjmax until you know the max offset.

All the E2xxx have 73C tcase 65W just like my E6850...I have no doubt they are 95-100c...I would use 100C.

the devious side of me thinks intel did this on purpose, along with heavy marketing for nehalem with accurate temp sensors that will display in degrees C, so any offsets will be read correctly by intel.
 
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owhsinchu

Junior Member
May 6, 2010
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LOUISSSSS said:
the new version of Real Temp allows custom settings for TJ MAX. Ver 2.70. i am wondering what the latest listing for the TJ MAX by Intel was for the Q6600 G0 stepping? thanks.

PS what are u guys using to monitor temps for the Q6600?
Click to expand...

What I have learned screening several forums regarding the exact same question:
First of all there are two different types of sensors. One sensor is located at the heat sink and is called Tcase. This sensor is obviously very correct and stable. I found that at room temperature and idle PC (not overclocked) it is very close to the MOBO sensor. At throttle PC (idle and not overclocked) and room temp the Tcase is exact the same as the ambient (room temp measured with an external digital thermometer near the CPU case). Intel provides a “maximum” Tcase value (Thermal specification) for each processor (similar that it provides a Vc max value) (Ref 1). These values should not be exceed otherwise it would affect the processors lifetime. For Q6600 G0 the Tcase “max” is 71C (see Intel spec sheets) and regarded as “hot” (similar Vc 1.55 shall not be exceeded). Intel also mentioned in a paper that 20C above Tcase silicon damage might occur (Ref 1). In the case of Q6600 G0 this would be 91C. This is the same temp at which the CPU will automatically throttle and then shut down (to force down-cooling). There are several programs that provide the read-out of Tcase. My feeling is that this is a good way to monitor CPU heat. For example at idle PC (overclocked, 24C room temp and a zalman-type of fan) my Tcase is 34C (with core temps between 36 and 40). At 100% load (small fft prime time) for 10 min it will reach 56C. Which means I am still 15C far from considered having a hot CPU (71-56 = 15). The distance to Tj max is 28 under this situation which means I am also far from reaching a critical situation. Tj max for Q6600 G0 is published by Intel to be 90C. Which makes sense as this is the temp the CPU will automatically shut down to prevent silicon damage. Even though there is a huge discussion about whether this value makes sense or not. One argument that this value makes sense is that it is close to the published value of Tcase + 20C for almost all CPUs (Ref 1). As Intel also publishes that a core temp (Tjmax – DTS) cannot regarded to be stable below 50C and measurements have shown that it can fluctuate of about +/- 30C at room temp (Ref 1) is it not surprising that when setting a Tj max of 90 we would receive values that might even went negative. Knowing this, a calibration (as suggested by Realtemp) would not make sense and would even increase the error. Setting Tjmax to 90C for a Q6600 G0 would result in my case (at 100% load for 10 min) in temperatures ranging from 63C (core 1 and 2) to 61C (core 3 and 4). This fits quite nicely with the assumption that there is a 7C difference between Tcase and core temp (IR thermometer measurements) using a better cooling fan (zalman etc). Even though I decided to watch my Tcase temps (instead of core temps) I would assume (and this is the only assumption here I make) reaching 78C (core 1 and 2) and 76 (core 3 and4) would be regarded as a hot core temp.

In conclusion, my personal opinion is that there should be a rethinking going on. Everybody is watching Vc and trying not to get it close to the published max value (for example Vc max 1.55). So why not simply watching Tcase and not trying to get it close to the Thermal Specification (71C in my case)?
(Ref1 http://www.overclock.net/intel-cpus/476469-truth-about-temperatures-voltages.html
 
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Borealis7

Platinum Member
Oct 19, 2006
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the Tom's Hardware article says G0 E6000 series has TJmax of 80C, i find that hard to believe since i have a slightly overclocked E6550 under a CM Hyper 212 and it idles at 60C-62C distance from TJMax = less than 20C (Vc is 1.152 at lowest idle) which is impossible because room temp is above 20C for sure, and last time i checked CM Hyper 212 is not a water setup.

i've seen many figures go around, i'd rather set mine to TJMax = 90C in RealTemp which makes things look alot more realistic.
 
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