Question Can a CPU be too cold?

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
I know it sounds like a odd question, and I suppose in fairness it is, but I am wondering, Can a CPU be too cold? currently I have an older CPU ( AMD FX 6300) and my idle temp is around 2-4°C, where I see other people say their CPU run at mid 20's. I only have Air cooling ( Cooler master hyper 212) Running prime 95 for awhile (around an hour) peaks the CPU temp to just 15°C. Should I be concerned the temps are so low or should I just be happy with everything running so cold, My worry is more or less from possible condensation, anyway any info would be greatly appreciated.
 

Math Geek

Titan
Ambassador
pretty much not possible to have those temps unless the pc is sitting in an icebox. something is wrong with the software or the sensors reading the temps.

normal room temp is usually around 20 C give or take a few. not really going to be able to maintain below room temps on air under a torture test. just not gonna happen.
 

Zephyl

Commendable
Mar 13, 2017
377
52
1,740
Condensation shouldn't be an issue if you're just air cooling (Edit: That is, unless you have ice sitting on the cooler or something.) As long as you're not chilling below the ambient temperature. The cold itself shouldn't damage the CPU, either. Most CPUs have a minimum operating temperature of -20C. Also, if it's not too prying, how are you accomplishing these temps?
 

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
ive used both HW monitor and Speccy to see the Temps and they both say the same, Idle my CPU is around 2-4°c , My room ambient Temp is 16° ( I dont like it overly warm) . All I did was replace the thermal paste and I only have 2 fans in case ( 1 intake, 1 exhaust)
I am not sure how to post a picture in the form but I did take a screen shot, as I type this With just edge and my torrent client running BOTH speccy and HW monitor state my CPU is now 9°C under stress using prime 95 HW monitor indicates max temp was 18°C , I always use 2 monitoring software and I cannot believe both pieces of software are inaccurate. Maybe I just have a cool running CPU? got lucky? I really have no explanation. I will try post a pic of Speccy
 

TJ Hooker

Titan
Ambassador
A lot of utilities don't read temperatures properly on FX CPUs, plus the temperature sensors themselves aren't that accurate at lower temps to begin with IIRC.

Your CPU is not running at or below ambient temperature. It is physically impossible without exotic cooling (e.g. refrigerated cooler). If your room temp is 16C I guarantee your CPU got hotter than 18C under full load. The most accurate/reliable way to measure temperature on AMD CPUs is to use AMD Overdrive and measure thermal margin. But that just tells you how far you are away from the max temperature limit, not the actually temperature in degrees celsius.
 
Last edited:

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
Condensation shouldn't be an issue if you're just air cooling (Edit: That is, unless you have ice sitting on the cooler or something.) As long as you're not chilling below the ambient temperature. The cold itself shouldn't damage the CPU, either. Most CPUs have a minimum operating temperature of -20C. Also, if it's not too prying, how are you accomplishing these temps?

To be honest I'm not 100% sure, I have replaced the thermal paste with some made from noctua (NT-H1) as well I have a cooler master hyper 212 cooler pushing air threw with a exhaust fan behind it and a front intake fan My CPU fan (according to the utility for my MOBO is only running around 20% speed.) my case does have 3 other fans (which I have shut off) 2 on the top (one directly above the CPU cooler and one in front of it) as well as 1 on the side panel. I have these unplugged though as I have noticed no significant temperature difference's with all them running. I have also adjusted the windows power settings from High performance to Balanced. but other that that I have not done anything, and No I dont have ice inside the case.. lol..
 
Your issue is two fold, as already mentioned most temperature measuring softwares wont properly report FX series temps, you have to use AMD Overdrive and check your thermal margin.

The second issue is the FX series habit to report false temps at low levels, their temperature sensors cant handle low temps well (because really they dont need to), so if you are seeing these sub ambient temps (outside of AMD OD), ignore them.
 
Is impossible CPU temp is lower than ambient, you would have truly found some alien technology.

Most likely whatever app you are using is not reading the correct sensor. This happens, these apps make certain assumptions and sometimes they err. Try another App. The temp reading on BIOS, if available, tend to be the most accurate.
 
Last edited:

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
A lot of utilities don't read temperatures properly on FX CPUs, plus the temperature sensors themselves aren't that accurate at lower temps to begin with IIRC.

Your CPU is not running at or below ambient temperature. It is physically impossible without exotic cooling (e.g. refrigerated cooler). If your room temp is 16 I guarantee your CPU got hotter than 18 under full load. The most accurate/reliable way to measure temperature on AMD CPUs is to use AMD Overdrive and measure thermal margin. But that just tells you how far you are away from the max temperature limit, not the actually temperature in degrees celsius.



AMD overdrive states thermal margin is 63.9°C ( Idle with just edge running) I'm not too sure what that means though, other than from what you stated my CPU temperature could raise another 63.9°C before it dies, but this at least makes more sense, I think my CPU can reach the 90's (but not sure ) before chance of killing it, so using basic logic I would assume if the CPU can go up another 68 degree then my CPU must be running around 22-23°C. which makes a lot more sense. the Irony is I always check with another program , in this case both Speccy and HWmonitor for results as I tend to never believe just one. and they both were indicating the same data. assuming I am correct on how I am reading the results from Overdrive I think its solved, hehe Moral of story use 3 programs to get results lol...
 
Last edited:

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
Is that thermal margin what is being reported under load? Max temp for your CPU is 70.5C according to AMD. I'm not 100% sure it's as easy as taking max rated temp - thermal margin = current temp though.


no that was just idle, I just finished running prime 95 ( I use the small fft for max heat) and thermal margins went to 53.5 and stayed there for a couple minutes. so if my max temp is 70°C and thermal margin is 53.5 than under load my CPU is reaching temps around 16.5°C? this still seems in line with HWmonitor but the idle temp would be 6° , and that is still way below my ambient room temperature. maybe sensors are bad or something, I assume all three programs would use the same sensor data
 

TJ Hooker

Titan
Ambassador
As said above, the sensors aren't accurate at low temps. I would guess either your CPU is staying cool enough that you're not getting into the range of temps where sensors are accurate, or the sensor is just outright faulty.

Are you running P95 with 6 threads? What frequency does your CPU run at while P95 is running?

Edit: Would you mind posting a screenshot of the thermal margin tab while P95 is running? Your previous links don't work for me, just upload to imgur and link to that.
 

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
could it be the cores run at different speeds due to the AMD cool and quiet in the bios? I think that is made to turbo some cores and slow down others , but Im not to sure if that is how it works. but I am sort of thinking the sensors maybe bad as well. my CPU fan never throttles however, and I know that works properly as I can adjust the settings to have it throttle at whatever temp, and it seems to work properly, by default it is set to throttle at 40°C and it has never throttled once.
 
You can try to disable that setting and see how it goes.
The main issue is any fan control is going off of temps, which are reported by guess what, the faulty sensor.
If you arent having any performance issues (downclocking) or crashes, I wouldnt be too terribly concerned about it.
 
  • Like
Reactions: TJ Hooker
D

Deleted member 14196

Guest
yes, agreed. faulty sensors, there is no way it's running that cold... even with liquid cooling it could never get that low, unless maybe it's liquid nitrogen LOL

as mentioned before, if it's working well, don't worry
 

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
ya machine works fine never crashes due to hardware issues, perhaps to be safe though Ill adjust my fan throttle temperature to a lower than default setting. I am almost sure now it is a sensor issue. because the fan will throttle if I set the settings low enough.
 

Gfost73

Reputable
Mar 23, 2019
520
66
5,090
Just an update, Last night I decided to remove the CPU cooler ( Cooler master hyper 212) and put back the stock AMD cooler that came with the system. I have noticed that the Temperatures now read normal, or at least seems more normal than 2°C, Currently my CPU is reading about 24°C, and when under stress peaks around 39°C. I think its safe to say there was some issue with the CPU cooler mounting, which I cannot seem to explain, perhaps it was over tightened, yet I did leave it looser than bottoming out the screws the cooler was making my RAM act up ( only using 4 of the 8Gb) but I think I have solved this issue, using the stock cooler seems to have worked.