# CPU running hot



## Jordian (Oct 12, 2005)

How hot is your cpu supposed to run? While not working, mine runs at about 65 or so. While working (installing, playing games) it spikes up into the 70s and occasionally into the 80s (celsius. 

1) How hot is a cpu supposed to run?

2) What steps can I take to cool it down, if needed? (I have a core2)

I've already added thermal paste, but maybe I added too much?

Also, my case has pretty good cooling. CPU fan, graphics card fan, huge back of the case fan, front case fan, psu fan. So why is it running so hot?

Keep in mind that these measurements are from Pc ProbeII that came with my Asus motherboard. Not sure if it's accurate or not, but this sounds like it's running very hot. Oddly enough, the computer doesn't feel hot.


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## Rashiki (Sep 29, 2005)

Yea, that's pretty dang hot, especially for a core2. What are the comlete specs for your computer? 

When you start up the computer, enter the BIOS and just double check that the temperatures are what the PCProbe says.

You said you added thermal paste... please describe how you put the paste on, and you put the heatsink/fan on the cpu. If there was already a thermal pad and you added paste, you'll have to take it apart and do it right. How tight is the heatsink on the board? It shouldn't move. 

Make sure the fan is blowing down across the heatsink for adequate flow. The fan in front of the case should be drawing air in, and the one in back of the case should be blowing out, creating a crossflow. 

Tie back all stray wires that may be disrupting flow, and blow any dust out.


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## Jordian (Oct 12, 2005)

Rashiki said:


> Yea, that's pretty dang hot, especially for a core2. What are the comlete specs for your computer?
> 
> When you start up the computer, enter the BIOS and just double check that the temperatures are what the PCProbe says.
> 
> ...


I just built it.

By thermal paste, I mean about 1/2 a grain for the cpu metal covering, and about the same thing for the heatsink bottom.

Specs:

Asus P5B (LGA 775)
Intel Core2 E6400
Antec Sonata II (case)
ATI X1800 256 mgb
OCZ Gold 1GB (2 x 512MB)

It's really odd. I didn't add a whole lot of thermal paste at all, infact not much at all. The case itself seems to be very cool and nothing feels hot at all. Makes me very worried. I actually added some thermal paste to what they had, so I guess I should take some off, but not much, because from what I remember, they added alot. The heatsink is on tight. 

I guess what i'll do is remove the heatsink (if I can, I put it in there reaalll good) and see if I can't get rid of some thermal paste.

Hmmm...when I start up, Bios doesnt appear and I cant even access it. Usually you press f2, but it doesnt even give me the option. Maybe thats why it's running so hot?


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## Dr. Leach (Sep 9, 2006)

What thermal paste are you using? imho the best way to apply it is spreading it out with a credit card or something similar. And remember the thermal paste is only really for filling in the microscopic gaps between the heat spreader on the cpu and the base of the heatsink. Only apply a small layer (the paste shouldn't ''ouzz'' out the sides when you press the heatsink on)

80ºC is really hot, i hope its reading it wrong :S

Artic Silver 5 is good stuff if you can get your hands on some.


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## Jordian (Oct 12, 2005)

Im using this formula 5 stuff from Antec. No dice though. I redid all the thermal paste, exactly as par with the instructions, and still im getting readings in the 70s. What the heck. Checked bios, nothing out of the ordinary. 

Do you think its possible that this pc probe might be wrong? I mean, if my cpu was that hot, don't you think I would feel the hot air it's transfering from my heatsink? Don't you think that I would feel some sort of heat? The pc probe says 79 celsius, yet when I feel the air from the heatsink, it's nice and cool. Weird huh.

Is it possible that maybe the PC probe sensor that measures temp could be messed up? Or is there an excellent track record with pc probe?

Oh, and how do I get the actual core temp in bios?


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## chauffeur2 (Feb 7, 2006)

Hi Jordian,



> Checked bios, nothing out of the ordinary. Do you think its possible that this pc probe might be wrong?


A couple of things to note here...

Firstly, I would trust the BIOS over the Asus PC Probe any day of the week, as my wife has the Asus PC Probe installed also [she's got an Asus Board], and the temps are never [in my opinion] very accurate at all.
The BIOS reads temps in the low to mid 30's C, yet the PC Probe says that its in the upper 40's to low 50's C.
I have a MSI board, and the PC4 Alert that they give you is absolutely useless [again in my opinion], as the Fan readings are [after ½ hr's running are showing that they are at Zero RPM!], which is ridiculous as you can hear and see them spinning quite normally.
To put your mind at ease, I suggest that you go here, and download Everest™ Home Edition. This is a very reliable and comprehensive monitor that gives all RPM's and Temps, as well as a bunch of other 'good to know' information about your computer.
You will know in your own mind that the results that Everest™ gives you are far more realistic than what you have been subjected to lately.:winkgrin: 

Secondly, most CPU manufacturers supply their CPU/heatsinks with a 'Thermal Paste Pad' pre-installed; which means that there is no necessity to apply further Thermal Paste, in fact you should only use one or the other _not_ both!
If you intend to use Artic Silver™ or similar, carefully remove the 'Thermal Pad' _before_ applying.

Hopefully this information has been useful to you, and not confused the issue any further. :grin:


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## Jordian (Oct 12, 2005)

yeah I think my biggest mistake was adding more thermal paste when there was already some there. I wiped it off and redid it but im still getting high temps. How exactly do I access the core temps through bios?

Okay bios says the CPU is running at 57 celsius. Much, much lower than the 80s I was getting through pc probe, but still running hot. So im back to square one again. I redid the thermal paste, I have a good heatsink and good ventilation (tons of fans in my comp case). It's not hot outside or inside. I still can't explain why it's hot. It is running cooler than before. I was messing with the heatsink, so maybe it's in more securely or something.


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## Dr. Leach (Sep 9, 2006)

But remember 57ºC in BIOS is the 'idle' temperature (when the cpu isnt doing much) and once in windows using applications/games,etc the temperature will rise even more.

What does everest report?

You can always buy a 3rd party sensor to get a accurate reading if you are worried.


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## dai (Jul 2, 2004)

http://www.arcticsilver.com/arctic_silver_instructions.htm


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## linderman (May 20, 2005)

PSU maker and model please ??????


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## Jordian (Oct 12, 2005)

Actually I believe the problem is a bad temp sensor. I touched the heatsink and it felt cool, so the cpu isnt that hot. Also, I left it off for a few hours, then I turned it on and went directly to bios, and it said the cpu temp was 70 celsius. Thats not physically possible. I dont believe anything can go from 20 celsius (room temp) to 70 in 6 seconds.


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## Rashiki (Sep 29, 2005)

So just to confirm, you scraped the square thermal pad off the heatsink? The clear plastic came off as well? I know you said you wiped off the paste you applied, but the pads don't just wipe off, you have to scrape at them.


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## dido1983 (Sep 13, 2009)

Jordian said:


> Actually I believe the problem is a bad temp sensor. I touched the heatsink and it felt cool, so the cpu isnt that hot. Also, I left it off for a few hours, then I turned it on and went directly to bios, and it said the cpu temp was 70 celsius. Thats not physically possible. I dont believe anything can go from 20 celsius (room temp) to 70 in 6 seconds.


Trust me, dude, such electronics can go 70 Celcius in 6 seconds like that!

Actually, the CPU, if powered on without heatsink and a fan can potentially reach in excess of 350 C (662 F) in a matter of seconds!!!

If you don't believe, watch this -- YouTube - CPU Burn (and these are so old, outdated CPUs).


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## greenbrucelee (Apr 24, 2007)

download real temp (this is for core 2 duo cpus) and set the TJ max to 95 for both cores and tell us what it says.

But as linderman has asked what is the make and model of your PSU?


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