# Which sensor is my CPU ?

## doublehp

```
Jan 31 12:13:21 uranus sensord:   temp1: 38.0 C (min = 127.0 C, max = 127.0 C)

Jan 31 12:13:21 uranus sensord:   temp2: 41.0 C (min = 127.0 C, max = 70.0 C)

Jan 31 12:13:21 uranus sensord:   temp3: 48.0 C (min = 127.0 C, max = 127.0 C)

```

I know the first one is my system / mother board.

But, i wonder which one is the CPU, and ... what is the 3rd probe. The BIOS menu only give two values.

I also wonder where are physically located the probes:

- Gigabyte MA785GT-UD3H

- AMD Sempron II 965.

I guess the 3rd one may be RAM, or chipset ? unless the second probe is soldered behind the CPU, and then the 3rd one could be inside the core ?

When i had a 245, 2nd and 3rd temp where always identical (or at most, 3° delta; but usually only 1); but since I switched to my new 965 (and changed the heat sink), it is 6 or 7° of delta.

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## bjlockie

Not sure but this might help:

http://www.runtimeaccess.com/articles/sensors/sensors.html

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## haarp

Good question. Create some CPU load and see which goes up, that's the CPU sensor.

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## energyman76b

Some mobos have a chipset plus and 'environment' sensor that measures the temp around the CPU. This temp will be a bit lower than the CPU temp and is important if you are building your computer following the cooling guidelines from AMD and INTEL which talk a lot about the case temp and not so much about the cpu temperature  :Wink: 

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## haarp

 *energyman76b wrote:*   

> Some mobos have a chipset plus and 'environment' sensor that measures the temp around the CPU. This temp will be a bit lower than the CPU temp and is important if you are building your computer following the cooling guidelines from AMD and INTEL which talk a lot about the case temp and not so much about the cpu temperature 

 

Most of the newer boards I know read the CPU temp directly and export it through their SuperIO chips. So yes, it's quite possible that the chipset sensor reads the actual CPU temp.

On the other hand, I'm still waiting for the amdfam10temp module.

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## aCOSwt

 *energyman76b wrote:*   

> Some mobos have a chipset plus and 'environment' sensor that measures the temp around the CPU. This temp will be a bit lower than the CPU temp...

 

Interesting indeed !

I was wondering about the meaning of my boologs :

```
Feb  5 08:18:02 [kernel] [    0.290945] coretemp coretemp.0: Using relative temperature scale!

Feb  5 08:18:02 [kernel] [    0.291699] coretemp coretemp.1: Using relative temperature scale!
```

relative to what ?

Would you explain this as "relative to the environment sensor" ?

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## energyman76b

that depends  :Wink: 

you should look up the cooling design guides for your cpu.

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## energyman76b

 *haarp wrote:*   

>  *energyman76b wrote:*   Some mobos have a chipset plus and 'environment' sensor that measures the temp around the CPU. This temp will be a bit lower than the CPU temp and is important if you are building your computer following the cooling guidelines from AMD and INTEL which talk a lot about the case temp and not so much about the cpu temperature  
> 
> Most of the newer boards I know read the CPU temp directly and export it through their SuperIO chips. So yes, it's quite possible that the chipset sensor reads the actual CPU temp.
> 
> On the other hand, I'm still waiting for the amdfam10temp module.

 

no, they don't. They have a sensor below the cpu.

You can't really read out 'the' temperature because (at least for intel) almost every cpu generates the values differently and with each cpu sub class it means something differently. Look up the documentation for your specific cpu.

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## haarp

 *Quote:*   

> no, they don't. They have a sensor below the cpu.

 

Wrong. It's been a while since I've last seen a board with this setup. Must've been around 5 years ago, probably more  :Wink: 

 *Quote:*   

> You can't really read out 'the' temperature because (at least for intel) almost every cpu generates the values differently and with each cpu sub class it means something differently. Look up the documentation for your specific cpu.

 

True. Usually, the temperature is the delta to Tjmax (maximum junction temperature). If you know Tjmax, you know the temp. And even if you don't you can still guess with a pretty high accuracy. (most modern temp monitoring programs did this until Intel released the docs regarding Tjmax)

Some CPUs are able to report the temperature inside each individual core. But there's also an "overall" temp that gets reported to the board for emergency shutdown and fanspeed controlling. This maybe the average temp of all cores, or the hottest among the cores. Depends on the CPU.

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## DaggyStyle

 *doublehp wrote:*   

> 
> 
> I also wonder where are physically located the probes:
> 
> - Gigabyte MA785GT-UD3H
> ...

 

there isn't any sempron II 965 cpu, do you mean the phenom II 965?

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## energyman76b

 *haarp wrote:*   

>  *Quote:*   no, they don't. They have a sensor below the cpu. 
> 
> Wrong. It's been a while since I've last seen a board with this setup. Must've been around 5 years ago, probably more 
> 
>  *Quote:*   You can't really read out 'the' temperature because (at least for intel) almost every cpu generates the values differently and with each cpu sub class it means something differently. Look up the documentation for your specific cpu. 
> ...

 

and sometimes it is a delta to Tcase. Or something completely different. It is a huge, freaking mess.

And you are wrong about the sensors - just because they don't look like the ones 5years ago does not mean that they aren't there.

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## doublehp

Probe 1 really seem to be the system. Probes 2 and 3 both increase at the same time with load. So, there is no software way to determine which one is the CPU, and what is the other one.

Probe 3 has always been hiher than 2; from 1° to 10° more.

Since I have changer my AMD provided CPU by the Noctua NH-U12P, probe 2 got really lower, and probe 3 got a bit lower. My actual CPU is AMD 965 (very recent revision). Then, the difference between 2 and 3 was between 6 and 12°. Yesterday I have put a very small fan on the chipset; since then, 3 got cooler, 2 and 3 always have the same value (1 or 2° delta). Even under load.

So, 2 really seem to be the CPU, and 3 really seem to be the chipset (north or south ?).

DaggyStyle you are right, it's was a Phenom II 465, and got now a Phenom IV 965  :Smile: 

energyman76b yes, old sensors used to be varistors on plastick stuff, and are now CMS diodes soldered directly inside the socket. So in fact, they are further from the core than before, and are cooled by the MB epoxy (so the given value is lower than the actual temperature of the air in the socket). But, more and mode CPU embeded a probe inside the core.

Any of you ... tell me if the Phenom 965 got an internal probe.

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## energyman76b

yes, the Phenom II got an internal probe. And as a am3 cpu it even should give accurate results.

You need 2.6.33 and you might have to give the force parameter when loading the driver.

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## doublehp

I need 2.6.33 to get what ? what don't I already have ?

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## energyman76b

you need kernel 2.6.33 to get the driver for using the internal probe.

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## doublehp

And then, activate which driver ? and use which software ? (rerun sensor-detect, or sth else ? )

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## DaggyStyle

 *doublehp wrote:*   

> 
> 
> DaggyStyle you are right, it's was a Phenom II 465, and got now a Phenom IV 965 
> 
> 

 

correction, you've got phenom II 965  :Wink: 

there is not such cpu phenom VI.

what strikes me oddin your problem is that you don't see all cores. am I right?

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## doublehp

If there was a Phenom VI, I'd have bought it; that's why I bought a Phenom FOUR !!!

I Phenoms II And IV, I always saw only one probe. Maybe missing drivers in kernel ? 2.6.31-xen-r10-Gentoo-uranus-1-12 , sensors 3. I don't know if i should have 1 or 4 temps. Maybe a soft miss-conf. MB is Gygabyte MA785GT-UD3H ...

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## energyman76b

 *doublehp wrote:*   

> And then, activate which driver ? and use which software ? (rerun sensor-detect, or sth else ? )

 

in .33? look unter hardware monitoring - the driver is called k10temp.

You don't need to r erun sensors-detect. That will only tell you which modules to load. Just load the driver with the force=1 parameter. Then run sensors, tada, you get your cpu sensor.

And to make it loaded on startup, add it to the right config file.

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## DaggyStyle

 *doublehp wrote:*   

> If there was a Phenom VI, I'd have bought it; that's why I bought a Phenom FOUR !!!
> 
> I Phenoms II And IV, I always saw only one probe. Maybe missing drivers in kernel ? 2.6.31-xen-r10-Gentoo-uranus-1-12 , sensors 3. I don't know if i should have 1 or 4 temps. Maybe a soft miss-conf. MB is Gygabyte MA785GT-UD3H ...

 

I really don't understand what you mean, is this you're cpu? http://www.newegg.com/Product/Product.aspx?Item=N82E16819103727

if so, then you should have 4 cores and thus atleast 5 sensor reading (1 per core + mb) if that isn't the case, post the relevant .config part here

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## doublehp

No, this is not my core. My core is more recent. It's also x4 965 2M/L2 Black, but 8M/L3 and a more recent stepping. OPN: HDZ965FBGMBOX. I have been said that the important part of the OPN is the "M". Which (if I am right) determines 8M/L3, recent stepping, and improoved ISA (also also 160W instead of 125 ^^ ).

But all those details should not affect the fact that I have 4 cores, and, I should be able to monitor them.

And, I was confused between the ... Phenom *II* *x4* ... sorry for confusion.

So, two questions remain:

- should I see 5 temps (or only one) under my 2.6.31 ?

- how can I know *for sure* if my 3rd probe is the chipset or not ? and if yes, is it north or south bridge ?

energyman76b : I am waiting for 2.6.33-xen to be released; maint told me that ebuild is out (since 48h), need to sync to see if I can unmask it ( https://bugs.gentoo.org/show_bug.cgi?id=258378 - 24h per day are not enough for me; I may not have time to search for k10temp before the WE. Still, I found k8temp ... so, I now know where to look, and udnerstand what I am missing).

DaggyStyle do you have a multicore Phenom ? do you see all the temps ? in sensors ? what's your conf (kver and so ... ) ?

Thanks for help  :Smile: 

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## DaggyStyle

 *doublehp wrote:*   

> No, this is not my core. My core is more recent. It's also x4 965 2M/L2 Black, but 8M/L3 and a more recent stepping. OPN: HDZ965FBGMBOX. I have been said that the important part of the OPN is the "M". Which (if I am right) determines 8M/L3, recent stepping, and improoved ISA (also also 160W instead of 125 ^^ ).
> 
> But all those details should not affect the fact that I have 4 cores, and, I should be able to monitor them.
> 
> And, I was confused between the ... Phenom *II* *x4* ... sorry for confusion.
> ...

 

I don't have a phenom II quad but I've seen topic about it, can you post your config?

there isn't any phenom II 965 with 8m L3 and 160w TDP... googling you're opn gives the exact cpu I've posted. so there can be 2 options, the first is that you're wrong, the second is that you're an amd employee and you are using an unreleased cpu.

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## doublehp

Again, you are right: 2M-L2 + 6M-L3 = 8. I misread some labels ... (so many things to read when buying a new PC ... )

What do you want to know about my config ? (any file to poste may be 100 or 1000 lines, so, before pasting anything, what do you want to know exactly ? cpuinfo ? config.gz ? lshw ? )

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## energyman76b

Phenom II 955:

sensors

w83627ehf-isa-0290

Adapter: ISA adapter

Vcore:       +0.98 V  (min =  +0.00 V, max =  +1.74 V)   

in1:         +0.14 V  (min =  +2.04 V, max =  +2.04 V)   ALARM

AVCC:        +3.30 V  (min =  +2.98 V, max =  +3.63 V)   

VCC:         +3.30 V  (min =  +2.98 V, max =  +3.63 V)   

in4:         +1.69 V  (min =  +1.53 V, max =  +2.04 V)   

in5:         +1.70 V  (min =  +1.91 V, max =  +2.02 V)   ALARM

in6:         +1.86 V  (min =  +2.04 V, max =  +2.01 V)   ALARM

3VSB:        +3.28 V  (min =  +2.98 V, max =  +3.63 V)   

Vbat:        +3.26 V  (min =  +2.70 V, max =  +3.30 V)   

in9:         +1.65 V  (min =  +2.04 V, max =  +1.78 V)   ALARM

fan1:          0 RPM  (min = 10546 RPM, div = 128)  ALARM

fan2:        409 RPM  (min =    0 RPM, div = 32)

fan3:          0 RPM  (min =    0 RPM, div = 128)

fan5:          0 RPM  (min =    0 RPM, div = 128)

temp1:       +31.0°C  (high =  -5.0°C, hyst = +125.0°C)  sensor = thermistor

temp2:       +46.5°C  (high = +80.0°C, hyst = +75.0°C)  sensor = thermistor

temp3:       +45.5°C  (high = +80.0°C, hyst = +75.0°C)  sensor = thermistor

cpu0_vid:   +0.375 V

k10temp-pci-00c3

Adapter: PCI adapter

temp1:       +51.6°C  (high = +70.0°C)      

k10temp loaded with force=1 option since I have an am2+ board.

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## Monkeh

Phenoms do not have multiple core sensors. They have one.

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