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Topic Title: Cpu or Core temp
Topic Summary: what is the more critical!!!
Created On: 04/21/2009 06:18 PM
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 04/21/2009 06:18 PM
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moorhen2
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Well i think we need to get a difinitive answer to this question.Amd state max operating temp for 940be is 62c,ok,now is that the cpu temp or the core temp,some would say the core temp is the critical one,others would say the cpu temp is the critical one,so my question is,who's right and who's wrong.???

I think we should try and get as many opinions and feedback on this subject as possible,i think it's a topic we would all like a difinitive answer to,one way or the other,so who's going to start the ball rolling.??

My money's on Kaz,lol!!

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Edited: 04/21/2009 at 06:26 PM by moorhen2
 04/21/2009 06:45 PM
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RBR
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I've wondered about this myself when looking at the temp specs. My CPU temp is always a few degrees higher than the core temps, so I figure if that one is well below the threshold, then everything is fine. I'll be interested to see the reply from others on this topic too.

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 04/21/2009 07:05 PM
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cvsi3
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Ive always gone by the Core temps, they are actually on the chip temps, where as the cpu temp is part of the motherboard. So its reading from the motherboard and not the chip itself.

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 04/21/2009 07:05 PM
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Bongsolo
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I have wondered this myself. Everest reports my CPU temp at or around 118c, while my core temps are around 33c.

Now, that CPU temp is extremely high and I would think that if that were indeed correct I would have fried my CPU a long time ago - so I think it's wrong.

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 04/21/2009 09:02 PM
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kazgirl
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I've been having a bad spell lately so am a bit slow in replying... my own preference is to go by whichever is the higher of the 2, as a better sae than sorry method.... but generally I use the Core Temps rather than the CPU temp, for the same reason mentioned above... the core temps are more likley to be accurate IMO... the CPU temp as per above is a temp reported by the mobo sensor not the CPU itself...!!!

But for overclocking purposes I go by the higher of the 2 temps... in my case there is generally only a 1-2C difference between the 2 anyway....

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 04/21/2009 10:18 PM
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Two7Buckeye
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Originally posted by: Bongsolo

I have wondered this myself. Everest reports my CPU temp at or around 118c, while my core temps are around 33c.



Now, that CPU temp is extremely high and I would think that if that were indeed correct I would have fried my CPU a long time ago - so I think it's wrong.



its certainly wrong. Im curious if you need a BIOS update.




My core temps are always about 8*C higher than my CPU temps. I watch both, and have gotten answers both ways.

Id like to know as well

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 04/22/2009 02:36 AM
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Edgemeal
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Last I read AMDs chips are rated by Tcase, (older chips like K7 were rated by the die temp, which is why you'd see K7s with 85C and 95C ratings).

Tcase is the temp taken at the center of the CPUs metal cover, this is the rating heatsink makers use when designing a thermal solution for an AMD CPU so they know if their product is suitable for a particular CPU part or not, their solution must be able to keep the Tcase at or below AMDs rating under full load and run within a certain ambient (pc case) temperature, in one of the AMDs builders/thermal docs it shows how to perform these tests.

Motherboard/Bios makers know the mathematical equation needed to report the CPU temp, it's usually taken from a single thermal diode in the CPU.

If you are using software that directly reads the CPU core(s) temps then that number is basically useless (for K8 and older) since you have absolutely no official core temp rating from AMD to compare it to.

Your best bet is to first go by the CPU temp numbers reported by the software that was made for/came with your motherboard maker, if it's totally unrealistic then its probably an outdated bios/software for your CPU.

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Edited: 04/22/2009 at 02:45 AM by Edgemeal
 04/22/2009 07:16 AM
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kazgirl
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Hi this is what the CoreTemp developer page says about the measuring of AMD CPU temps....


http://www.alcpu.com/CoreTemp/howitworks.html


    The temperature readings are very accurate as the data is collected from a Digital Thermal Sensor (or DTS) which is located in each individual processing core, near the hottest part. This sensor is digital, which means it doesn't rely on an external circuit located on the motherboard to report temperature, its value is stored in a special register in the processor so any software can access and read it. This eliminates any inaccuracy that can be caused by external motherboard circuits and sensors and then different types of programs trying to read those sensors.

      AMD chips report the temperature by a special register in the CPU's NB. Core Temp reads that register and uses a formula provided by AMD to calculate the current temperature.

        The formula for the K8 is: 'Core Temp = Value - 49'.
        The formula for the K10* is: 'CPU Temp** = Value / 8'.


      The sensor in AMD CPUs can report temperatures between -49C and 206C.


    *K10 = Phenom (Agena), Opteron (Barcelona). The K10 reports a temperature value that is relative to a certain predefined value, it doesn't report the actual processor temperature! So take that into consideration.
    **CPU Temp is because the Phenom\Opteron (K10) have only one sensor per package, meaning there is only one reading per processor
    .


Please note however that the CPU Temp referred to above is not the CPU Temp commonly used by most monitoring tools, the CPU Temp that is reported by tools like HWMonitor and Everest is in fact the temperature being reported by the motherboard sensor and not the CPU DTS sensor.... it normally is a value taken from a diode sensor that sits on the motherboard under/near the CPU socket itself... which is why generally the CPU Temp is AFAIK considered to be less accurate than the Core Temp value that is reported...!!

But my own recomendation to people is to always use whichever value is the higher of the 2, on the basis that it is better to err on the side of caution... of course if the values are totally unrealistic then its indicative of BIOS/Software being out of date or not supporting the CPU in use...

Common examples can be where a BIOS is being used that doesn't fully support the CPU.... or monitoring software hasn't been updated to include the support for a newer CPU.... first thing to check is that both the BIOS and the monitoring software you have is up to date and supports the hardware you are using....

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3DMark06 = 20717 / 3DMark Vantage = P13618 / My Overclock Guide / My Troubleshooting Guide

Edited: 04/22/2009 at 07:24 AM by kazgirl
 04/22/2009 10:54 AM
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Immortal Lobster
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I've always used the core temp readng for the reasons listed above.

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 04/22/2009 05:45 PM
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Xerran
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On my Q6600 and now my Deneb the core temps are higher than the CPU temps so I set Everest to shut down my system if core temps breach 55c (AMD states no higher than 62c) just to be safe.

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 04/22/2009 06:39 PM
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RBR
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I always use Everest but just downloaded Core Temp 0.99.4 based upon posts here, and it almost mirrors Everest. The TCase Max reading is greyed out in Core Temp with no value though, so I'm not too sure yet what that is about.

Everest

CPU: 33c
Core 1: 27c
Core 2: 30c

CoreTemp
Core 1: 27c
Core 2: 29c

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 04/22/2009 06:53 PM
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kazgirl
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Yes AFAIK Everest uses the same sensor to acquire and report the Core Temp values as CoreTemp 0.99.4 does.... the dfference between the 2 is that Everest also displays the CPU Temp that is reported by the mobo sensor in addition to the Core Temps reported by the CPU Diode sensor....whereas CoreTEmp 0.99.4 doesn't bother with the motherbaord sensor reading, and just displays the core temps from the CPU Diode sensor...

I usually use the 2 in conjunciton, just to verify that readings obtained with Everest are correct, once I'm satisfied that Everest is reproting the same as CoreTEmp then Ijust use Everest for day to day use.... until I get a new CPU or mobo etc... at which time I check again with the latest version of each... (CoreTEmp and Everest) to amke sure that the new hardware (Mobo/cpu) is supported by the software... some mobo sensor chips or Super I/O chips aren't always supported by Everest until an updated version is released...

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 04/22/2009 07:29 PM
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RBR
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Thanks Kaz. Apparently Everest is serving me well then. I'll keep your advice in mind though when I upgrade someday...

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 04/23/2009 02:40 AM
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Edgemeal
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Originally posted by: Xerran

On my Q6600 and now my Deneb the core temps are higher than the CPU temps so I set Everest to shut down my system if core temps breach 55c (AMD states no higher than 62c) just to be safe.


They should be higher, and the max core temp ratings are a lot higher then the Tcase ratings, so you just can't compare a core temp reading to a Tcase rating, totally two different things. You have to go by how the chip maker rates the max temp and how that temp is supposed to be taken, if you don't you might as well check the air in your car tires with a water pressure gauge.

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 06/29/2010 02:36 PM
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magdiel1975
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i spoke with AMD rep today and the guy told me that when AMD states the max temps on a cpu, they mean the "cpu temp" and not the "core temp"..core temps are supposed to be hotter due to the fact that they are located on the hottest part of the cpu..My phenom II 965 maxes "cpu temp" 50c and "core temp" of 55-57c.
So, when AMD says the max temp is 62c..they mean for the CPU Temp (over all temp) not the cores.

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 06/29/2010 03:51 PM
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PC-GURU -
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boy is yours backwards from 1090T.

30c CPU temp and core temps is 19c each lol

965 BE was the same the core temp was always lower.

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 06/29/2010 04:18 PM
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magdiel1975
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i forgot to mention that I have my phenom 965 OC'ed to 3.8ghz, 1.42v.ran stability test for 5 hrs and the max temp went up to 55c then after an hour or so, it came down to 53 on air using V1 cooler.

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 06/30/2010 04:16 PM
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Spellshaper
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I go with core temp. My MB fan management reacts to CPU temp, and I found that I get errors and BSODs when core temp exceeds 63-64°C when under heavy load after a period of idling. When core temp hits that mark, CPU temp is still at ~56°C. It will catch up sooner or later if the load stays the same, but core temp seems more reliably tied to system stability.

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 07/01/2010 07:58 AM
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Immortal Lobster
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Don't go by core temp, it's a bogus number. it's based on a mathematical function of input voltage, speed, and usage, with a few other spices tossed in. I ran acros the eq. somewhere on AMDs site, if I have the time, I'll see if I can't dig it back out. but Core Temp is not to be relied on. Use the Motherboards CPU sensor.

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 07/01/2010 08:22 PM
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Spellshaper
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and there goes my reasoning :s

Well, at least it's a so-so indicator for immediate system stability.. sometimes

Good to know Lobster.

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