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strange very low temps

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September 9, 2007 1:43:23 PM

hi all
went round a friends house to do a bit of TAT on his new C2D E6750 and for some reason its reporting idel temps as 18 deg c and rises to around 28 under 100% load, but my E6600 has idel temps of 48 deg c and 65 under 100% ??? what is going on here ???

cheers
Mike

More about : strange low temps

September 9, 2007 1:45:52 PM

sorry for repost :( 
September 9, 2007 2:16:05 PM

Defective temp monitor/defective chip probably. Maybe if it is water cooled and you are in a chilly air-conditioned house (for icy cold water cooling) it is possible. On air cooling, most likely the chip is faulty. Is there an AC duct for central AC coming out of the floor near the comp?? That would do it... some AC ducts pour out tons of icy cool air in some offices I have worked at to the point I needed a sweater on in the summer LOL.
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September 9, 2007 2:27:51 PM

pickie said:
hi all
went round a friends house to do a bit of TAT on his new C2D E6750 and for some reason its reporting idel temps as 18 deg c and rises to around 28 under 100% load, but my E6600 has idel temps of 48 deg c and 65 under 100% ??? what is going on here ???

cheers
Mike

Having seen similar temps from an E6850 & an E6400 here in sunny England, I reckon you need to check the HSF on your E6600.

P.S My Q6600 regularly idles @ 27-28c and barely hits 40c under load.
September 9, 2007 3:02:35 PM

-"P.S My Q6600 regularly idles @ 27-28c and barely hits 40c under load."

Yes, so knock off an extra 8-10C in a cold AC environment ~30C load.

So it sounds silly, but the ambient temps make quite a difference. Most people fail to mention their ambient temps or take it into consideration. They'll see on a cool summer day "wow my temps are good" and on a hot day with no AC "why are my temps so high??".

Mousemonkey is probably using stock HSF for that too... unless my ambient temp theory was a wrong impression I picked up along the way that needs to be cleared up... I learn tons of new stuff off THG that nothing surprises me anymore LOL.
September 9, 2007 3:17:26 PM




If you see above, 1 is when it's idle. The other photo is when it's just finish doing PI tests. OC to 3.7Ghz using 6750 and still 29 degree C when idle. So I don't think you're at low temps. I think it's quite normal. My room temperature is 25 degree c here. Case has 6 silent fans.
September 9, 2007 3:27:30 PM

Yes, pickie, I am going to have to look like a n00b here and just congratulate your buddy on having a well-working, cool, brand new PC. I really don't think there is anything wrong with it.

To put his mind at ease, if it is still bothering you or him that it isn't working well, run Prime95 and see if it passes for a couple of hours with the side of the case off and TOUCH the heatsink with your fingers to see if it is ACTUALLY cool or warmish to the touch.

If it is HOT to the touch, well, the CPU is reporting wrong temps and you should RMA it IF IT REPORTS COOL TEMPS IN THE BIOS.

Cool temps in Bios + Cool to the touch +runs Prime 95 on ALL CORES and has no errors after 24 hours torture test = a bunch of drooling THG readers :) 
September 9, 2007 3:28:09 PM

repost
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September 9, 2007 3:35:57 PM

pickie said:
but my E6600 has idel temps of 48 deg c and 65 under 100% ??? what is going on here ???

cheers
Mike


Mousemonkey said:
Having seen similar temps from an E6850 & an E6400 here in sunny England, I reckon you need to check the HSF on your E6600

I suggested that it was the OP's CPU that was running too hot. Not his friends E6750 running too cold.

Falken699 said:
-"P.S My Q6600 regularly idles @ 27-28c and barely hits 40c under load."Mousemonkey is probably using stock HSF for that too... unless my ambient temp theory was a wrong impression I picked up along the way that needs to be cleared up... I learn tons of new stuff off THG that nothing surprises me anymore LOL.


I'm using an Arctic Freezer pro 7 on my Q6600, but the E6850 and an E6400 that I mentioned, were running stock HSF's.
September 9, 2007 4:25:40 PM

wow cheers for the replys :)  TAT is reporting it as a pentium M ?? Mobile chip ??? the same as its reporting my E6600 so i guess TAT is reporting it ok ?
September 9, 2007 4:51:22 PM

Don't you have to add 15 Celsius to those new CPUs on the temperature reporting of them? I just read it somewhere and I don't remember the reason.
September 9, 2007 5:25:55 PM

Quote:
A/C vent near the comp? ROFL -Even if the A/c Vent was attached to the front of the case it wouldnt be 18c.



Quote:
A cpu is not going to run 18c unless the amibient temperature is below freezing which is highly unlikely indoors.


Are you getting Fahrenheit mixed up with Celsius here or what? When's the last time you checked the temp coming out of your A/C vent? You made me measure mine, just to prove you wrong. I have a cool 51 Fahrenheit blowing, which converts to 11 Celsius. My CPU never idles more than 6 degrees Celsius over ambient room temp. You can't tell me that I couldn't get 17-18C at idle if the intake air (ambient) was only 11C.
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September 9, 2007 5:39:04 PM

FSXFan, since the outflow temperature from an A/C vent will become thermally diluted as it mixes within the room, it is recommended for accuracey to measure ambient temperature near the computer case air intake, clear of warm exhaust currents. From the Core 2 Duo Temperature Guide: http://www.tomshardware.com/forum/221745-29-core-temper...

"Part 2: Tcase Offset Correction

(A) Measure Ambient, preferably near computer case air intake, clear of warm exhaust."

Hope this helps,

Comp :sol: 
September 9, 2007 6:10:13 PM

Quote:
A/C vent near the comp? ROFL -Even if the A/c Vent was attached to the front of the case it wouldnt be 18c.

Most likely tat doesnt recongnize the chip. What does tat identify the chip as at the top?



Sorry to say, but you are mistaken. A/C outlet temps should be 40-50 degrees F cooler than the air going in. You could easily chill your CPU to lower than 18C if the A/C vent was close to your computer.

@ Falken699

You shouldn't necessarily RMA a CPU if it reports bad temps. It might not be the CPU at all. Some motherboards take the voltage from the temperature and convert it itself, so it could be the MB is reading the temps wrong.

When it comes to temps on the computer, they don't have to be perfect. It could be that you disabled the Intel Speedstep and so it's defaulting to the lowest speed and that's why it's running so cool. I know I made this mistake on my laptop. I thought "If I disable speedstep i'll force it run at the highest frequency". Instead it locked in at 1.0Ghz on my 2.16Ghz chip. It was about a week before I realized what was wrong because some programs say 2.16Ghz because that's the rated speed of the chip, others reported 1.0Ghz because that's the actual speed it was running at. It was hard to figure out the difference when I knew the processor could do either speed at any given time.

I now use Rightmark on my laptop because it'll show me the actual speed of the CPU, and I can set thresholds on when it changes frequencies and shows me a cool little icon on my taskbar showing my actual CPU speed. It regularly jumps from 1.00 to 2.16Ghz and back.

Directed at everyone:

I'm seeing more and more comments of people saying 'that's impossible' and whatnot when in fact it is possible. Don't dilute the forum by saying things aren't possible when in fact they could be. Not to flame anyone(and this is also from previous posts i've read). Sure a CPU temp of 18C is low, but it's possible. Please be sure you are fully informed as to what is and isn't possible before you try to claim it's not. Any of us(including myself) don't know the whole situation of the computer. It's more constructive to offer ideas on what could be wrong than what's impossible. Obviously a CPU that says -100C is clearly in error. Anyone posting in a forum about a CPU temp and lists -100C is clearly very educated in the IT field, and will provide ample information to get a few replies to his problem.

Most people posting here having problems have run out of ideas themselves, and are hoping someone else has seen the same problem. Unfortunately they don't know the answer, so the information that might be key to the problem might be insignificant to them. Take this situation for instance. 18C CPU temp. Seems like something is wrong so he posted. Someone mentioned the A/C unit outlet might be giving a good cool inlet to the computer. Very valid arguement, and I'm convinced that most people wouldn't write down that their computer sits next to the vent. You can't type about everything that is going on with your computer. If you did you'd write a 10 page question talking about EVERYTHING about your computer, include engineering drawings and photos of the inside of your case, the room your computer is in, every single component and how it was installed(especially CPU/heastink installs) so that we know every single detail. It's not logical to write about every single detail, but to cover the most likely culprits to start.

------------------------------
-The smartest people don't always know the most. The smartest people know what they DON'T know.
September 9, 2007 6:43:58 PM

Nice one cyberjock, but actually I think most people would say that their pcs are right next to the vent, but whatever.
What Pickie needs to do is run different temp programs like coretemps and speedfan and such to see if they are giving the same temps (Tjunction is another issue). He also needs to measure the temps in the room. TAT showed that his friend's cpu at 100% was 28C, so that rules out speedstep. And if his cpu really is running at those really low temps at room temps, then something is clearly wrong, and I don't know what.
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September 9, 2007 7:02:47 PM

Evilonigiri and cyberjock, I agree. I am sincerely interested in helping as many of Tom's users as I can reach to understand temperatures, uniformly test, accurately calibrate, and properly monitor their systems, so please read the Core 2 Duo Temperature Guide: http://www.tomshardware.com/forum/221745-29-core-temper...

To everyone; the questions asked in this thread have answers which are already available in the Guide. Even if some of you have read this Sticky before, it is frequently updated, (most recently September 4th), and now includes a section on Calibrations. Respectfully, please save yourselves some time, eliminate speculation, and become informed on this topic by reading the Guide.

sycshk, your temperatures are inverted as well as inaccurate. With repect to air cooling, (ambient correctly sampled near the computer case air intake), NO computer temperatures are below ambient, Core temperatures are NOT below ambient, and Core temperatures are NOT below the CPU temperature. Please read the Guide, and Calibrate your temperatures.

Again, I hope this helps,

Comp :sol: 
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September 9, 2007 8:07:06 PM

nightscope said:
Don't you have to add 15 Celsius to those new CPUs on the temperature reporting of them? I just read it somewhere and I don't remember the reason.
We have a winner! Those new 6x50 series (G0 stepping) use Tjunction,max value of 100C instead the previous 85C, so all those monitoring software show it 15C degrees too low.....
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September 9, 2007 8:16:15 PM

yeah that guide is nice and complex :p P
But every software that I have tried are giving me below ambient readings for my 6550....
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September 9, 2007 8:27:01 PM

Kari, the Guide is intended to provide enough information for users to understand and calibrate their temperatures. If you find it "complex", it is by design, since providing too little information does not serve to adequately answer everyone's questions. If you're looking for a quick and easy solution, then I can't help you, however if you read the Guide carefully and follow the Calibrations section, then you can configure Offset corrections within SpeedFan, so that your temperatures will be properly displayed. Many others have successfully used the Guide to resolve their temperatures issues, so you should be able to do the same.

Comp :sol: 
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September 9, 2007 8:35:09 PM

I knew you were going to say something like that :) 
But I just meant that all the software that i have tried so far are misreading the Tjunctionmax, CoreTemp 0.95, SpeedFan 4.32, TAT, Asus' own motherboard utility, to name a few

edit: but yeah, I might try to do some calibration but not right now, it's close to midnight here and I'm off to bed
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September 9, 2007 8:42:24 PM

That's OK, because we can work around it. This is why the Guide now includes a Calibrations section. We can correctly identify temperatures, and since SpeedFan is one of the only utilities which will allow Offset corrections to be configured, we can still display accurate temperatures.

Comp :sol: 
September 10, 2007 3:46:58 AM

CompuTronix said:
FSXFan, since the outflow temperature from an A/C vent will become thermally diluted as it mixes within the room, it is recommended for accuracey to measure ambient temperature near the computer case air intake, clear of warm exhaust currents. From the Core 2 Duo Temperature Guide: http://www.tomshardware.com/forum/221745-29-core-temper...


Not my point at all. I only meant to prove MrsBytch wrong for saying that "Even if the A/c Vent was attached to the front of the case it wouldnt be 18c". I know it's not a likely scenario and the OP didn't even mention an A/C vent. I just think that some people should use their heads a little more before they post about things sometimes. To quote Cyberjock "Don't dilute the forum by saying things aren't possible when in fact they could be."
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September 10, 2007 6:16:25 AM

FSXFan, understood and agreed. Fair enough.

Comp :sol: 
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September 10, 2007 6:52:01 AM

I've found CoreTemp to report my 3700 as low as 18C, it was pretty chilly, but it certainly wasn't below freezing. That was with a clock speed of 1.8GHz and a vcore of 1.1V with my cpu fan at max.

EDIT: Oh and unfortunately, that was idle not load :( 
September 10, 2007 9:14:21 PM

Quote:
Prove me wrong LOL. Ok lets take a poll. How many people think that the 18C that his cpu is reporting is the correct temp?? Thanks, have a nice day.
Ok if the ambient temp was 12c then yes the cpu could be 18c. BUT WHO IN THE HELL RUNS THEIR A/C AT 52F??????????????????? GET REAL DUDE! I THINK YOU SHOULD USE YOUR HEAD BEFORE POSTING SOMETHING SO RIDICULOUS.


Are you calling me a liar? I measured the temp an inch above the A/C vent at 51C yesterday morning. That's pretty comparable to most of the houses around my area. I was a heat and air technician for years, don't question me about who runs their A/C that cold.

I wasn't arguing whether the CPU was reporting the correct temps or not. Again, just saying that if someone indeed had their A/C vent attached directly to their case (which was the scenario you stated), a temp of 18C IS POSSIBLE, which you just freakin admitted! You should grow up and learn to quit making comments on subjects you know little of. I'm done with this conversation, my head hurts from thinking down to your level. :sarcastic: 
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September 11, 2007 5:52:47 AM

Quote:
What other programs have you compared it with? what does your bios report? Your cpu is not running at 18c unless your running your a/c in the low 50's fahr.

I didn't bother to check with any other programs and I'm sure it wasn't really that temp. As I said it was pretty cold that day and my case has good ventilation, plus I had undervolted and underclocked heavily, but I still don't believe it was that low.
September 11, 2007 6:29:33 AM

@ Bytch:

You clearly didn't read my post earlier.

Quote:
Sorry to say, but you are mistaken. A/C outlet temps should be 40-50 degrees F cooler than the air going in. You could easily chill your CPU to lower than 18C if the A/C vent was close to your computer.


I know someone that set up their computer to take inlet from inside their house, and their exhaust went outside. Is it super rare, yeah. Is it likely no.

To quote you:

Quote:
Prove me wrong LOL. Ok lets take a poll. How many people think that the 18C that his cpu is reporting is the correct temp?? Thanks, have a nice day.
Ok if the ambient temp was 12c then yes the cpu could be 18c. BUT WHO IN THE HELL RUNS THEIR A/C AT 52F??????????????????? GET REAL DUDE! I THINK YOU SHOULD USE YOUR HEAD BEFORE POSTING SOMETHING SO RIDICULOUS.


Guess what? If you set your A/C to 80F, the air coming out isn't 80F, it'll be 50F or so. The temperature on the thermostat will cycle on and off at 80F. And put this in your pipe and smoke it. I've heard from quite a few A/C technicians(I have a family member that works in the field) that a car's A/C unit has the capacity to remove more BTUs/hr than an average A/C unit in a house! I haven't researched it, but A/C systems and what temps should be where are clearly not your strong point. Please read up on A/C units, the actual amount of heat removed, temps going in and out, efficiency of A/C systems and why they suck so bad, THEN post about this topic. If I ran my A/C in the low 50s, my A/C would be on 24x7 as the efficiency of freon at lower temperatures declines(as well as higher outside temps causes efficiency to decline) to the point where I could get it no colder, but the A/C would run 24x7 maintaining a temperature. You ever turn on your car's A/C on a very humid day and you get the fog like look out of your vent? That's ice that's in the air from your A/C. Your A/C unit cooled the air so much it reached freezing, and it was so humid it didn't condense all of the air, but some of the moisture in the air froze. 0C baby!

To answer YOUR questions:

I think it's possible. Did the poster tell you where he/she lives? I live in WA state, and I don't turn the heat on in my computer room in the winter. 18C is a common CPU temp idle for me in Dec/Jan. On the flip side of that I had a quad processor(not core) Xeon machine 2 years ago. And in the winter I would run folding programs on all 4 processors to make heat. When did I have to turn the heat on in my apartment? When it snowed and it stuck! I helped keep myself warm plus helped find a cure/aliens/whatever.

So your poll is now 1 against you. :)  Read my signature please. Then read it again. I'm sure your missing something between the first letter and the period at the end.

Have a wonderful day everyone!
!