asus 478 boards report wrong cpu temps!

[saaya]

http://www.legitreviews.com/Reviews/coretemp_1.shtml

they suggest its just a "misinterpretation" of the readings from the internal core temp sensor. they tested an abit max3 and a asus p4c boards temp readings and the diference in reported temps with the same cpu, same vcore, same fsb, same oc, same cooling was as high as 14°C!

this is not a asus monitoring software problem, mbm5 reads the temps wrong as well!

[pkrew]

Honesly, I'm not sure which one would be off by the most. I had a temp probe under the cpu when I was running a max3 and it read 10C lower at idle and around 5C lower at load then AbitEQ. I'm not sure how accurate cpu temp probes are, but I suspect that the real temp for both boards is somewhere in the middle of the two reading they got in the article.

[Soulburner]

This is a known issue, mine is way under the real temp.

[saaya]

the termal diode is inside the core, remmeber that! so you will ALWAYS get lower readings close to the cores, no matter how close you are, than from the internal diode. even if you would meassure the temp directly on the surface of the core it would be lower than the actual core temp inside the cpu.

people are used to see lower temps because historically we have always meassured the temps close to the core, not even the surface of the core. its ok to lower the readings of the internal diode a bit to make the temps look like what they would be with a termal probe inside the socket or close to the core, but IF you change the temps you have to tell the people that the cpu temp is actually higher than displayed.

lowering the temp reading by 15°C however is more than adjusting the reading to make it comparable to socket temp probes...

[Smoking_Red]

Originally posted by saaya
the termal diode is inside the core, remmeber that!
There are two of them! one is for the overheatingprotection...when cpu reach 135°C system will shutdown and restarts only if temp has droped to normal value...second one is for measure the cpu-temp...but this reports only to the smd-chip witch is located at the mainboard....Here is a statement from abit... http://forum.abit-usa.com/showthread.php?s=&threadid=11496

The way CPU temperature measured in the BIOS or in the hardware monitor is through an I/O chip on the motherboard. That I/O chip probes a voltage given by the CPU thermal diode, and then BIOS / hardware monitor reads this value and uses some mathematical way to calculate the approximate temperature. According to Intel, there is another temperature sensing diode, which is responsible for the CPU overheating protection. When the CPU junction temperature reaches approximately 135 degrees Celsius (275 degrees F), the processor will turn down itself. That is, we can say the CPU is quite safe if it is less then 135 degrees Celsius (275 degrees F).

Since the temperature is “calculated”, not “measured”, the formula which the BIOS uses will make the outcome different. There is a parameter that is provided by the I/O chip vender, which we expect it to be the standard, so we use this parameter to calculate the temperature of the processor.

[saaya]

1st: name of the thread: ASUS 478 boards report wrong cpu temps!
2nd: read the link i posted ;) says the same thing like the abit quote you posted...

its about asus, not abit! abit uses some algorythms that are adjusted very nicely to what the REAL cpu temp is like. asus boards instead report much lower temps than they really are.

[joeyddr]

not for nothing but who says that the abit temps are correct? if anything i would think the asus board si more close since its pretty close to the intel board.

[Soulburner]

Doubt it joey, if the Abit reports higher temps I would believe it over the ASUS, they are rediculously low, to the point where I was supposedly at idle at 26c at 3ghz last summer.

[saaya]

yepp, i think abit is the only one or one of the few who actually worked on the interpretion of the signals from the internal diode while asus and other only copied the intel algorythm wich was probably only given to them as an example on how to deal with the readings and not a suggested final solution.

i really wouldnt have expected this from asus...

[Soulburner]

I take it as "what they want you to think" your CPU temps are.

The average joe wouldn't know any better.

[saaya]

yeah i thougt the same, but i dont think anybody buys an asus board because it shows lower cpu temps... doesnt matter why the boards are 15°C off, they should fix this asap!

[joeyddr]

yeah but the asus temps are closer to the intel board

[saaya]

so what? doesnt mean they are correct. somebody needs to meassure the temps with a probe and compare it to the bios/mbm5 temp on an abit board.

[st0nedpenguin]

Well I'm currently sat here idling at 25/27 for CPU/MB temps, on air, that sounds just a little bit off. :)

[Soulburner]

Originally posted by st0nedpenguin
Well I'm currently sat here idling at 25/27 for CPU/MB temps, on air, that sounds just a little bit off. :)
That's what mine would say too but (hell it said 26c CPU idle last summer) but I stopped using ASUS Probe, I have an LCD readout.

[saaya]

is the lcd displaying the cpu diode temps or the temps of a termal probe? if yes, wheres the probe located and what does it read compared to the asus crap? :D

[pkrew]

First, I have no doubt that the Asus is reading low. However, I'm also confident that the max3 reads high. These are determined mathmatically, there's no way we can know which is more accurate and both are probably off to some degree. Even the engineers at intel probably dont know the true temp of the core. How could you get an accurate measurement. The algorhythms are mathmatical guesswork. The other thing that I wonder is why my AI7 reads the same cpu and overclock at lower temps. Did Abit change their way of calculating on the AI7. If they did, why?

[Soulburner]

Originally posted by saaya
is the lcd displaying the cpu diode temps or the temps of a termal probe? if yes, wheres the probe located and what does it read compared to the asus crap? :D
Its placed on the back of the CPU and it reads 35c when ASUS says 26c.

At 50c load ASUS only reports 38c. I think my probe is pretty accurate.

[FreZhm@ker]

IMO you cant use the mobo for measuring temps at all! I've had 3 mobos with the samme cooling and clock:

Abit IC7 Mac2: 59´C load
Abit AI7 #1: 46´C load
Abit AI7 #2: 56´C load

I rest my case!

[saaya]

hmz could it be the cpu itself?

ive had the same cpu on 7 boards with the same cooler and the temps reported by the internal temp diode are always pretty much the same under load an in idle...

8rda+
nf7-s
nf7-s
nf7-s
nf7-s
a7n8x
k7vt2 (kt266a)

[pkrew]

well, that was an amd cpu and I've had the same experience with the abits I've had. The first max3 I had read about 56C load the second was about 60C load and the AI7 is 52C load. The systems were identicle in every way except the mb. The temp probe that I used at the time was thermal taped to the underside of the cpu and read 50C at load for the max3s. I haven't used it on the AI7 and got rid of the case as I was tired of looking at it.