temp monitoring diodes

[Lez Pawl]

First Q, would it be normal for the system temp to be higher than the cpu
temp.

Second Q, I have a Foxconn MoBo supplied with monitoring software SuperStep.
This shows CPU at 30C and System Temp at 41C.

I also use, as it can be set to display on the Taskbar, MBM5 and was under
the impression from plenty Googling, ITE8712F-1 was the CPU diode and
ITE8712F-2 the System..............but they show 43C and 33C respectively
which is the reverse (almost) of SuperStep..

should I consider that these diodes on the Foxconn board are reversed.

 

[Rod Speed]

First Q, would it be normal for the system temp to be higher than the cpu temp.
Nope.

Second Q, I have a Foxconn MoBo supplied with monitoring software
SuperStep. This shows CPU at 30C and System Temp at 41C.

Something's wrong.

I also use, as it can be set to display on the Taskbar, MBM5 and was
under the impression from plenty Googling, ITE8712F-1 was the CPU
diode and ITE8712F-2 the System..............but they show 43C and
33C respectively which is the reverse (almost) of SuperStep..

should I consider that these diodes on the Foxconn board are reversed.

See what Everest says.

 

[paulmd]

First Q, would it be normal for the system temp to be higher than the cpu
temp.

Unusual, but it may be expected if you have a good CPU cooler, and a
poor case airflow.

 

[Paul]

First Q, would it be normal for the system temp to be higher than the cpu
temp.

Second Q, I have a Foxconn MoBo supplied with monitoring software SuperStep.
This shows CPU at 30C and System Temp at 41C.

I also use, as it can be set to display on the Taskbar, MBM5 and was under
the impression from plenty Googling, ITE8712F-1 was the CPU diode and
ITE8712F-2 the System..............but they show 43C and 33C respectively
which is the reverse (almost) of SuperStep..

should I consider that these diodes on the Foxconn board are reversed.

Every monitoring program makes assumptions about which sensor
is connected where. In addition, when it comes to sensed
voltages, there are resistor dividers next to the monitor
chip, and unless standard scaling values are used, then the
monitoring program will also read out the wrong voltages.
So a badly designed motherboard, that doesn't adhere to
defacto standards for placement of sensors, will screw
things up.

One way to determine something about the sensors, is to watch
the response to system load. Start a copy of Prime95, then
watch which sensor temp starts to climb. Both sensors will climb,
but the system temp sensor should take longer, as it will
take time to heat up the air inside the computer case. The
CPU temp sensor should climb faster.

In the past, when a CPU socket sensor was used, the monitor
programs used a "fudge factor" and a correction was added
to the socket temperature, to make it seem more realistic.
And that is another reason that several monitoring software
programs may not agree on the values seen. If the CPU has a
diode sensor, then no fudge needs to be added to make the
reading realistic.

Paul

 

[Rod Speed]

(e-mail address removed) wrote

Lez Pawl wrote

Unusual, but it may be expected if you have
a good CPU cooler, and a poor case airflow.

Nope, that cant produce the cpu temp lower than the internal case temp.

Basic physics.

 

[meow2222]

First Q, would it be normal for the system temp to be higher than the cpu
temp.

Second Q, I have a Foxconn MoBo supplied with monitoring software SuperStep.
This shows CPU at 30C and System Temp at 41C.

I also use, as it can be set to display on the Taskbar, MBM5 and was under
the impression from plenty Googling, ITE8712F-1 was the CPU diode and
ITE8712F-2 the System..............but they show 43C and 33C respectively
which is the reverse (almost) of SuperStep..

should I consider that these diodes on the Foxconn board are reversed.

These temps are very unlikely. Its possible (although most unlikely) if
the CPU sits by the air intake and uses intaked cool air, the CPU is
running way below speed and the psu has a fan on the intake side that
kicks hot air into the case, and youre in a cold room well below 30C...
but IRL its almost certainly wrong.

Solution is ignore the readings and check cpu temp with your hand.
Touching the cpu at bottom of HS it should not be hot enough to burn.
If it hurts too much to keep hand there, too hot. If it hurts but not a
lot, its around 60C.


NT

 

[Mike Walsh]

First Q, would it be normal for the system temp to be higher than the cpu
temp.
No.

Second Q, I have a Foxconn MoBo supplied with monitoring software SuperStep.
This shows CPU at 30C and System Temp at 41C.

I also use, as it can be set to display on the Taskbar, MBM5 and was under
the impression from plenty Googling, ITE8712F-1 was the CPU diode and
ITE8712F-2 the System..............but they show 43C and 33C respectively
which is the reverse (almost) of SuperStep..

should I consider that these diodes on the Foxconn board are reversed.

Yes. They are reversed on my Soyo board.

 

[John McGaw]

(e-mail address removed) wrote


Nope, that cant produce the cpu temp lower than the internal case temp.

Basic physics.

Yes it can. Basic physics or no. If the MB temperature sensor happens to
be located next to some extremely hot component and the general airflow
through the case is blocked from reaching that area then that sensor can
easily exceed the temperature of the CPU which, if it has a really good
HS and fan, may well be only a few degrees above the true case ambient.

 

[Rod Speed]

Yes it can. Basic physics or no.

Nope, the cpu will always be dissipating power and so its
temp will be higher than the ambient temp its running in.

If the MB temperature sensor happens to be located next to some extremely hot component

Doesnt happen.

and the general airflow through the case is blocked from reaching that area then that
sensor can easily exceed the temperature of the CPU which, if it has a really good HS
and fan, may well be only a few degrees above the true case ambient.

Fantasy with modern cpus.

 

[Rod Speed]

These temps are very unlikely. Its possible (although most unlikely)
if the CPU sits by the air intake and uses intaked cool air, the CPU
is running way below speed and the psu has a fan on the intake side
that kicks hot air into the case, and youre in a cold room well below
30C... but IRL its almost certainly wrong.

Solution is ignore the readings and check cpu temp with your hand.
Touching the cpu at bottom of HS it should not be hot enough to burn.
If it hurts too much to keep hand there, too hot. If it hurts but not
a lot, its around 60C.

Pity the two temps are 43C and 33C or 30C and 41C

 

[meow2222]

Pity the two temps are 43C and 33C or 30C and 41C

Its very unlikely those are the real temps, the readings are most
likely meaningless. a check with a hand is whats needed. Temp
monitoring is nice if youve got it, but when you havent the system
still should work quite happily.


NT

 

[meow2222]

Nope, the cpu will always be dissipating power and so its
temp will be higher than the ambient temp its running in.

Maybe someone's never heard of Peltiers.


NT

 

[Noozer]

Nope, that cant produce the cpu temp lower than the internal case

Maybe someone's never heard of Peltiers.

Or water cooling....

Or OTHER components putting out more heat than the CPU.

 

[kony]

First Q, would it be normal for the system temp to be higher than the cpu
temp.

It varies per system and use. Yes for one system and use it
could be normal, but not for another. It is fairly common
though, nothing to be alarmed about and further, it doesn't
really matter one way or the other so long as all parts in
your system stay below their own, individual temp spec. In
other words, CPU and system temp tell you nothing about the
other motherboard chips, HDDs, video card, etc, temps.

Most often when system temp is higher you have a specific
set of circumstances:

- CPU is mostly idle and an ACPI enabled OS is running, so
the HALT idle keeps the CPU cool. In such a case, running a
CPU stress test (like Prime95's Torture Test) should quickly
elevate the CPU temp.

- System temp is taken by another chip- so it is not really
a "system" temp, they just label it as "system" because that
is convenient, and since any chip may create heat itself, it
is actually warmer than the case air temp. Further, since
this other chip is not likely to be cooled by ACPI Idle
states, it's temp will be more of a reflection of the margin
between it and the chassis temp or total system thermals
(heat production vs airflow).

Second Q, I have a Foxconn MoBo supplied with monitoring software SuperStep.
This shows CPU at 30C and System Temp at 41C.

Find some way to confirm it is accurately reporting temps.
It is not uncommon for such programs to report wrong, or
reversed temps, particularly if the software isn't a fair
bit newer than the motherboard so it has been set properly
for that boad. Merely having the software come on the
motherboard CD is not evidence it is new enough,
unfortunately.

I also use, as it can be set to display on the Taskbar, MBM5 and was under
the impression from plenty Googling, ITE8712F-1 was the CPU diode and
ITE8712F-2 the System..............but they show 43C and 33C respectively
which is the reverse (almost) of SuperStep..

Don't ever assume you can install a 3rd party temperature
software and just use it, they always need set up for the
particular motherboard. Since they disagree with the
Foxconn supplied software odds are the Foxconn software is
correct, but as mentioned above it does not matter.

All that matters is whether any temp goes too high, and
you'll have to run stress tests for several hours to find
the peak temps. FWIW, the easier way to determine which is
CPU temp was mentioned above, that running Prime95's Torture
Test will make the CPU temp go up a lot more than the system
temp.

should I consider that these diodes on the Foxconn board are reversed.

Run the test.
Be sure to report back on your findings as it will be useful
to anyone else also pondering the same thing.

 

[Rod Speed]

(e-mail address removed) wrote

Rod Speed wrote

Maybe someone's never heard of Peltiers.

Maybe he would have said that it had one of those if it had one of those.

 

[Rod Speed]

Or water cooling....

Or maybe he would have said that it had that if it had had that.

Or OTHER components putting out more heat than the CPU.

Only in your pathetic little drug crazed hair splitting fantasyland.

 

[Rod Speed]

(e-mail address removed) wrote

Rod Speed wrote

Its very unlikely those are the real temps,

Bullshit. Both sets are reasonable in an
air conditioned room with the cpu idling.

the readings are most likely meaningless.

Unlikely to be meaningless when they are quite similar.

a check with a hand is whats needed.

Nope, because that wont indicated if the sensors are reversed in the display.

Temp monitoring is nice if youve got it, but when you
havent the system still should work quite happily.

Separate matter entirely to his question, whether they are likely reversed.

 

[Rod Speed]

It varies per system and use. Yes for one system and use it could be normal,

Very bloody unlikely indeed, particularly that alleged system temp and
the cpu temp being so much lower than that except with something
unusual like a peltier which he would have mentioned if he was doing that.

but not for another. It is fairly common though,

That reversal isnt.

nothing to be alarmed about and further, it doesn't
really matter one way or the other so long as all parts in
your system stay below their own, individual temp spec.

Not possible to know that if you dont know which sensor is which.

In other words, CPU and system temp tell you nothing about
the other motherboard chips, HDDs, video card, etc, temps.

Thats wrong too with the real system temp.

Most often when system temp is higher
you have a specific set of circumstances:

- CPU is mostly idle and an ACPI enabled OS is running, so
the HALT idle keeps the CPU cool. In such a case, running a
CPU stress test (like Prime95's Torture Test) should quickly
elevate the CPU temp.

- System temp is taken by another chip- so it is not really
a "system" temp, they just label it as "system" because that
is convenient, and since any chip may create heat itself, it
is actually warmer than the case air temp. Further, since
this other chip is not likely to be cooled by ACPI Idle
states, it's temp will be more of a reflection of the margin
between it and the chassis temp or total system thermals
(heat production vs airflow).

Find some way to confirm it is accurately reporting temps.
It is not uncommon for such programs to report wrong, or
reversed temps, particularly if the software isn't a fair
bit newer than the motherboard so it has been set properly
for that boad. Merely having the software come on the
motherboard CD is not evidence it is new enough, unfortunately.

Don't ever assume you can install a 3rd party
temperature software and just use it, they always
need set up for the particular motherboard.

No they dont.

Since they disagree with the Foxconn supplied
software odds are the Foxconn software is
correct, but as mentioned above it does not matter.

 

[kony]

Very bloody unlikely indeed, particularly that alleged system temp and
the cpu temp being so much lower than that except with something
unusual like a peltier which he would have mentioned if he was doing that.

No Rod, it's common. Any modern board with the temp sensor
in the north or southbridge and a non-P4-Prescott, for
example, might be expected to behave this way when
circumstances are as I described previously.

Note that you dont' have to agree for it to be true, and
unless the OP's temp readings are reversed, this is yet
another example of it happening.

That reversal isnt.


Not possible to know that if you dont know which sensor is which.

It is possible to determine it by observing the change in
temp when the CPU is changing state from mostly idle to
mostly (nearer full) loaded.

 

[paulmd]

Nope, the cpu will always be dissipating power and so its
temp will be higher than the ambient temp its running in.

That's true, as far as it goes. The CPU will be hotter than the AIR,
and PCB immediately it, but not necessiarialy hotter than the area
where the second temperature sensor is located. And given that
motherboards have more than one hot compenent. Some even requiring
additonal heatsinks and fans.

Doesnt happen.


Fantasy with modern cpus.

By no means. I had a thermaltake cooler on my Athlon 2600+, that caused
a drop in CPU temperature, after the new cooler, the CPU tempearture
was below system temperature.