# lm_sensors on Asus P2B, with Pentium2 400

## jpc82

I'm having problems getting lm_sensors working with my Pentium2, on an Asus P2B mobo.

Right now I have the modules loaded and everyting seems to work, but my CPU temps are not displayed.  My mobo temps, and ram size, and all other sensors seems to be displayign, but not my CPU temps.

Did the Pentium 2 400 not come with a termal sensor, or is something of mine setup wrong?

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## Purrkur

It is a question of wether your mobo has what it takes to report cpu temperature . I guess you got a socket 1 type of CPU there as well? I googled and found this:

"First of all, the motherboard has an excellent hardware monitoring system. It comes with the ambient case temperature sensor already installed and CPU and power supply heat sensors can be added. "

The page is here:

http://www.hardwarecentral.com/hardwarecentral/reviews/126/1/

You probably don't have the needed sensors mounted. Check out the documentation for your motherboard to check what is needed.

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## jpc82

I'm confused.

I thought that Intel chips had the thermal sensor built into the chip itself, and it was only the AMD chips which had the sensor built into the mobo.

When I get home I will search for the manual and see if it mentions anything.

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## Purrkur

Hello again jpc82/confused  :Smile: 

I think you might be confusing the thermal sensor for measuring heat to that which shuts off the cpu if heat becomes too great. In that case, I know that all new Intel CPU's have that kind of protection built in but I am unsure of your 400MHz Slot 1 Intel CPU.

OK, so here is the deal with heat sensors for CPU's on motherboards. If you have a ZIF socket CPU (that is one of those sockets with lots and lots of holes on it and a lever to lock the cpu into the socket itself), then usually the sensors is located in the middle of the ZIF socket. It usually sticks out far enaugh to measure the heat from the underside of your CPU. The values given should be considered a reference and not the real thing because you are not measuring core temperature here at all. Some say that you can increase the temperature by those sensors by 15 degrees C in order to get core temperatures. 

Now your CPU is not a socket CPU. It is contained in it's own casing and it sticks right out of the motherboard (it is called slot 1) which means that a CPU heat sensor cannot be located on the motherboard itself like it does with CPU's mounted on a ZIF socket. So therefore, I can just imagine that motherboard manufacturers provided a sensor input somewhere on the motherboard but the heat sensor itself has to be connected to it and placed somewhere on the CPU itself for heat detection. 

Please note that I don't have any Slot 1 based computers so I took the time to download and look at the manual for the P2B board. What I found pretty much sums up what I said above  :Smile: 

Look at page 22 in the manual (ASUS Smart Thermal Solutions). There you can see that you should have a sensor cable (ASUS P2T-Cable) that has a connector plug on one side and sensor on the other. The connector goes to the sensor connector on the motherboard while the sensor itself is glued onto the Slot1 CPU. There are pictures and instructions of this in your manual that show you how it should be done.

Hope this helps.

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## Admiral LSD

I've just been googling and apparently Intel CPUs as early as the Deschutes Pentium 2 (which is what that 400Mhz one should be, Deschutes P2's are the ones with the 100Mhz FSB) have had internal thermal monitoring diodes. This would explain why my old AX6BC was able to report the CPU temperature. Assuming this info is accurate, my guess would be that the P2B is just too old to support these meaning you'll either have to find the sensor cable or do without CPU temp monitoring.

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## jpc82

Admiral LSD`:

I really dont' think that this mobo is too old to have thermal support since the bios has a spot to view the current CPU temperater.  However, the value is N/A.

Purrkur:

As Admiral LSD` stated slot 1 CPU's can have thermal temp monitoring diodes built in, I even have an other PC which is slot 1 on a different mobo which has temp stats.  I wanted to try out this working CPU in the P2B, but they are not compatible.  Also, as far as I know only AMD chips have the thermal diode in the middle of the ZIF socket since they don't have on built into the CPU.  If you look at p3/p4 mobo's which support thermal stats you will not find one in the ZIF slot since they are actually built into the CPU.

Also, I looked over my manual and noticed it mentioned that it had a thermal sensor plug, however it didn't mention that it was suposed to be used for the CPU.  Maybe my manual is out of date, I will try downloading the current one from Asus when I get home.

Also, thanks for all the help and tips.

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## Admiral LSD

 *jpc82 wrote:*   

> Admiral LSD`:
> 
> I really dont' think that this mobo is too old to have thermal support since the bios has a spot to view the current CPU temperater.  However, the value is N/A.

 

That's not what I meant. What I meant was that the board is too old to support reading of the diode inside the chip itself. It relies totally on the data provided to it by the external thermal sensor. Since you don't have that sensor the reading is stuck at N/A.

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## jpc82

I must not have been clear.

I completly understude what you ment.  Thats why when I get a chance I will download the latest P2B manual to see if they explain it better then what my current one does, since the one that Purrkur found seems to explain it more clearly.

What I was saying is that I know that the CPU has suport for themal stats(whether the data comes from the CPU, or an exteranl sensors is another story), since that spot is there in the BIOS

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## Purrkur

jpc82: I gotta go with Admiral LSD' on this one. In my second post I wrote that the manual mentions a heat sensor on a sensor cable glued to the CPU. However, I failed to give you the location of the manual that I look at so here goes:

http://www.asuscom.de/pub/ASUS/mb/slot1/440bx/p2b/p2b(pcb1.02).pdf

I hope it provides what you are looking for.

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## jpc82

Thanks for all your help guys.

I have looked over the manual on asus's site and its completly diferent then the one I have, even the board is a little different, must be a newer revision

Looks like I will have to live without thermal stats on my CPU

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