Low CPU temps

[packratbob]

u sure thats ur cpu sensors?? or u bent ur temp sensor down i'd be more worried that ur temps are reading wrong then anything else

 

[lazerin]

i've stuck my in socket sensors onto the bottom of the cpu with ASIII. im pretty sure they r correct. altho the heatsink does get pretty hot. It is more like 27C when im doing normal stuff such as surfing n doing homework n editing multimedia stuff. but when i leave it for a while, it does go down.

 

[Arkaine23]

Cool temps

I would be more inclined to believe that there is another reason your temps can get so low...

A stock heatsink just isn't very efficient, even if the cpu isn't overclocked. Your duct is probably throwing off the sensor's accuracy. All that extra airflow also blasts around the socket area, and the traces of the pcb are all copper. You are probably experiencing the secondary cooling effect of this 21C air hitting the motherboard socket area.

 

[safemode]

nobody is refuting the idea that you are showing us what you saw.. But guess what. Your heatsink isn't a superconductor of heat. so face the facts and realize that your motherboard is reporting ****ed up temperatures.

You see the way a heatsink works is it's colder than the cpu core, thus heat transfers from the cpu core to the heatsink. Now see the heatsink is hotter than the air around it.. So it transfers this heat to the air. This is called heat dissipation / heat transfer etc. Now, your motherboard is saying your cpu core is 1 degree over ambient. This would basically have the heatsink doing nothing because the metal needs more of a difference than one degree over ambient to transfer heat in any practical way. So, take off your heatsink and run your computer. It's not doing anything anyway when your cpu core is 1 degree over ambient.


actually for that fact alone.. it's impossible to have an ambient temp 1 degree over ambient because the metal will have such a low heat conductivity that the cpu would be insulated and rise in temperature until the temperature difference of the heatsink and cpu are high enough for the element the heatsink's made out of to transfer the heat.

the cpu core temp heating up goes like this..

/ <-- core increases until
/ <-- balance reached
------ <-- heatsink transferring to air
/ <--|heatsink is equal to core
-----/ <--| but not hot enough to tran to air
^
|
Heating heatsink


It's kinda rough but what it says is the cpu core will have a minimum temp no smaller than the temp needed by the heatsink to transfer the core's power output to whatever is around the heatsink...be it air ..liquid or whatever.

So yea, anyways .... all of this was just to say that your sensors are completely screwed up.. if you dont believe so, find yourself a 25-30watt lightbulb and turn it on...wait about 5 minutes and then squeeze it with your bare hand. That's what your P4 is putting out if it's idle.

 

[packratbob]

i thought he had and xp1800

 

[safemode]

either one.. it doesn't matter which.. It's just more obviously wrong with an AMD chip because windows wont use the bus-disconnect feature with amd chips to turn them off during idle like P4's do. All amd chips get is the HLT treatment.

 

[dansonang]

when my ambient is 31 my idle is 32(min) but it can to to 35(max)at idle . I dun lie. I have got 2 different temp sensor to verify this. too bad I dun have a digicam. nah mind. but when it comes to load it goes to 42 at max no matter what ambient

 

[dansonang]

anyway i have got something to brag abt cos my ambient temp and my cpu temp is approximately in the same range

 

[safemode]

the ambient temp is reaching the temperature of the core at idle at around 32C for the P4. So yea, that's nothing to brag about. This thread is around because someone's sensors are telling them that their cpu is idle at 23C and ambient is around the same. That I can safely say is bull. Your reading is just normal considering the fact you have your computer running in hell.

 

[dansonang]

maybe. however to you, u may find that a computer running at 23 degrees idle is a problem, but to me I believe this is possible if yr ambient temp is lower than that for example 18 degree or aroud there.

I have seen japanese using some freezing techniques getting a cpu to negative degrees and overclock a 2.53b to 4.12ghz.

 

[safemode]

are you even reading the thread? the whole point it was even made was that he said he was getting 23C temps with a 22C ambient.

 

[Bigsexy]

Wanna see mine ?

 

[gone_fishin]

The thermister under the socket just isn't accurate to compare to other peoples temperatures but if you leave the cpu in socket so that the sensor doesn't move and test a different cooling setup like a new heatsink or change your fans, then it is good enough to gauge if there is an improvement, and that's about it.
I don't think it is a good idea to put ASIII on the probe, it is designed for use under clamp down pressure, you are just adding something inbetween the probe and the cpu to throw it off more.

 

[lazerin]

ok. i think this thread has gone far enough. I think everyone has expressed their opinion and I reckon people can believe whateva they want. As for me, I will double check on my CPU placement and have a good look at the probe to see whether anything is broken. All this talk about my temp reading wrong is scary. Must make sure its correct. I'll be borrowing one of those infrared thermometers soon, BUT, how am I suppose to get the reading of the temp with the heatsink still on?!

 

[safemode]

all you need to do is look at the temp of the heatsink.. if the temp of the heatsink is hotter than what your temp sensors say your core is then your temp sensors on the motherboard are obviously wrong.. i'd suggest doing this when it's saying you have a cpu temp 1C over ambient again. if the cpu was cooler than the heatsink then it would be getting hotter by the heatsink...and that just doesn't make sense.. so therefore the mobo sensor is hosed.

 

[lazerin]

ok, i'll give that a go. i only ever get 23C when i leave the comp for a long time and at stock speeds, which isn't very often. BUT i did find something that seemed a bit interesting. In the bios, the temps are idling at 25C when the ambient is 22C. But then i start up winxp and leave it for an hour or so and the temps are down to 23C. help explain?

 

[safemode]

all sensor programs take into account callibrations. Sometimes these are wrong. Usually they are correct and the temp readings are fairly accurate. Of course, there are examples where it's not and you have to recallibrate your sensors (if that's possible) or you may just have to deal with no temp sensors.

If they measure temp but are just offset wrong then it's easy to fix ...if they just plain aren't measuring temperature correctly then you're screwed. The only way to make sure is to monitor the same place that all the sensors are as best as you can. Good luck in trying to fix anything if you find that it's innacurate (heatsink hottor than core)

 

[lazerin]

BREAKTHROUGH!!!

I discovered why the temps were so low. I got a bit suspicious when I looked at the +12.00v readings on mbm five and they were reading at 11.5 instead of the usual 12.5v. I then looked at the task manager and found something called "cpucoolvd" or something and tried end tasking it. GUess what? the +12v reading went straight back up to 12.5v and the temps started to rise!!( i know this shouldn't be sometihng to get excited bout but what the hey ). Now they sit at 27C idle at 1533mhz.
I think i got that cpucool thing when i installed the actual prog cpucool to make a line graph of my temps. It must not have uninstalled properly. Oh well. drama over

 

[safemode]

sounds like it just sends the disconnect command more aggressively than the bios or kernel does. nothing magic there.


You'd see the downside of this in latency but if you're not doing anything dependent on that you wont notice it.

 

[packratbob]

i told u u had some softwhere cpu idle shutdown stuff it like the same as thos p4 with cpu shut down while idle