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Does my CPU have a bad heat sensor?

  • Yes

    Votes: 9 39%
  • No

    Votes: 14 61%
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Jodo Kast

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Discussion starter · #1 ·
That's correct. AMD Overdrive (and Speccy) show my AMD FX 6300 idling a 10-14 degrees Celsius with the stock cooler. But when I'm in the UEFI on my motherboard, on the hardware monitor page, it shows idle at 40-41 degrees Celsius.

In UEFI the Mainboard temp shows 36c. Speccy shows 37c for the Mainboard temp at idle. So does my CPU have a bad heat sensor?

Thanks!

Mobo: ASRock 990FX Extreme4
Bios : 2.00
CPU : AMD FX 6300
RAM : GeIL EVO CORSA 2 x 8GB DDR3 1866
HDD1: SAMSUNG 830 64GB SATA III
HDD2: WD Black 1TB 7200 RPM 64MB Cache SATA III
PSU : COOLER MASTER Silent Pro M 700W
OS : Windows 7 64-bit

P.S. I guess I should just be happy and overclock to 6 GHz
smile.gif
 
Software reading is wrong. Get coretemp or realtemp or HWmonitor.

There is no such thing as a too cold CPU. They are never cold enough
tongue.gif
 
Unless you're living in 10 Celsius conditions, it is impossible for that to be your CPU temp, so it definietly a dodgy sensor / dodgy software with AMD overdrive.
Download HWmonitor and tell us what temps you get there.
 
Inaccurate readings, the bios one sounds more like it. Just don't trust it, besides idle temps are very often inaccurate anyways. Are load temps somehow weird too?
Quote:
Originally Posted by Just a nickname View Post

Software reading is wrong. Get coretemp or realtemp or HWmonitor.
There is no such thing as a too cold CPU. They are never cold enough
tongue.gif
Not true
 
Discussion starter · #11 ·
Quote:
Originally Posted by Alatar View Post

Inaccurate readings, the bios one sounds more like it. Just don't trust it, besides idle temps are very often inaccurate anyways. Are load temps somehow weird too?
Not true
I got it up to 42C!...

I'm using the stock cooler, in case I somehow forgot to say that.

I can easily feel heat coming out of my case, so I know it's not as cold as it says it is... I just hope I'll be able to get a good reading in Windows so I can overclock some. I don't feel comfortable overclocking if I don't know the real temperature.

I made it up to 47C now....
Quote:
Originally Posted by $ilent View Post

Probably CPUTIN from that screenshot. Give coretemp a try, its pretty good.
My CPUTIN temps are a low of 38C and high of 52C (after about 2 minutes of 100% CPU usage). So what CPUID Hardware Monitor shows is probably my real temperature?
 
Quote:
Originally Posted by Derp View Post

I thought AMD measured core temperatures differently and as a result it is only accurate during load.
To elaborate on this;

I'm fairly certain (let's say 95%) that Thuban, Bulldozer, and Piledriver all use (and I believe previous incarnation Phenom) a calculated algorithm to get core temperatures. These readings due to whatever reason are not accurate until the cores hit 45c, and anything below 45c cannot be trusted to be accurate (under load). Idle temperatures mean nothing save for a relation against ambient temps.
Quote:
Originally Posted by Jodo Kast View Post

Quote:
Originally Posted by $ilent View Post

Probably CPUTIN from that screenshot. Give coretemp a try, its pretty good.
My CPUTIN temps are a low of 38C and high of 52C (after about 2 minutes of 100% CPU usage). So what CPUID Hardware Monitor shows is probably my real temperature?
This is probably the case. HWMonitor has things labeled wrong/misread.
 
My FX8350 idles at 0 or .1 Degrees C, ... just sayin' I dont think the Thermal Sensor reports the temps you need, my CPU Probe reports like 12 Degrees C when it says my Chip is .1

I think my chip reports that low because the IC Turns off unused cores.
 
12 Posts into this and nobody has been able to answer this correctly?

Your temperatures and temp sensors are fine. You motherboard has a built in sensor that measures the temps at the CPU socket. Your CPU ALSO has a built in temperature sensor , but due to the formula used to calculate this temp, it is only accurate under load. Your CORE temps are the ones that you need to look at and monitor under load when stress testing. I think the general consensus for Vishera is that your core temps should not exceed 60 degrees celcius.

Quote:
Originally Posted by ALUCARDVPR View Post

AMD Temp Information and Guide

We've had a few great threads recently where members contacted AMD and asked what temps they should be looking at, what the max temp was on, and what programs should be used and why. But this information is still scattered and not well defined in one place. It also doesn't quite explain when you should be looking at certain temps. Well I've made it my mission to insure that people are reading the right temps and have been trying my best to give all the information each time I respond without sounding like a broken record. So I decided to write this information thread and little guide to help you out there.

What is "Core Temp" ?

"Core Temp" is what AMD refers to as "TCTL" and is a non-physical temperature on an arbitrary scale measured in degrees. It does not represent an actual physical temperature like die or case temperature.

What is "CPU Temp" ?

"CPU Temp" is read by a sensor in the socket of the motherboard.
It is a physical temperature and therefore will be effected by ambient temps inside the case.

Why should I use "Core Temp" and when?

AMD designed this equation to accurately read peak (45C+) and load temps. It has an equational offset to determine said temps which equalizes at 45C. Since it's designed for peak temps and is a non-physical temperature it cannot read idle temps or account for ambient temps correctly.

So what is "CPU Temp" good for then?

At peak temps this value is typically 7-10C higher (depending on motherboard) than the actual temp due to it being a physical sensor. At idle it's a little more accurate, but still not dead on, and besides idle temps do not matter near as much as load temps do.

AMD says my chip has a [INSERT SPEC] Celsius limit, what value is this referring to? This limit seems kind of low, why?

This is referring to "Core Temp" of course.

So for example Phenom IIs have a recommended 62C "Core Temp" limit while not exceeding 60C for extended periods.

It has long been argued that the recommended limit is merely a larger safety net. There is a thermal shutdown in the chip at 90C and the silicone is rated for 97C+, so it seems plausable that we could indeed go higher, but this guide (and most in general) will simply *nod* and point you to the recommended limit for your chip.

What programs read "Core Temp" ?

AMD recommends the Core Temp program and AMD Overdrive for this reason.

The core section of HWMonitor also reads this value, but be careful as it also shows CPU Temp.

Where are you getting this information?

Aside from the great information threads below, I am a Mechanical & Computer Design Engineer who has several colleagues that either currently work in AMD's engineering department or used to.

Source: OCN Thread #931241
- Information from Alex Cromwell, Senior Technology Director, AMD

Source: OCN Thread #1095360
- Information from AMD Global Customer Care
 
Trust the BIOS. Also you can't be below ambient temp without phase change type cooling.

This is why temp monitoring software lets you adjust the readings
thumb.gif


Also, does AMD use a similar TjMax system like Intel? If so the closer you are to TjMax the more accurate the reading is.
 
Discussion starter · #16 ·
Quote:
Originally Posted by 2advanced View Post

12 Posts into this and nobody has been able to answer this correctly?
Your temperatures and temp sensors are fine. You motherboard has a built in sensor that measures the temps at the CPU socket. Your CPU ALSO has a built in temperature sensor , but due to the formula used to calculate this temp, it is only accurate under load. Your CORE temps are the ones that you need to look at and monitor under load when stress testing. I think the general consensus for Vishera is that your core temps should not exceed 60 degrees celcius.
Hey thanks a lot for the info!!
 
Quote:
Originally Posted by Jodo Kast View Post

Hey thanks a lot for the info!!
You're welcome. The CPUTIN reading is that of the Motherboards Socket Temp Sensor, and Core is that of the Processors own temp sensor. Good choice on selecting HWMonitor to view your temps/voltages.
Quote:
Originally Posted by GanjaSMK View Post

My summation wasn't enough?
tongue.gif
You pretty much hit the nail on the head except for the part about HWMONITOR mis-reading temperatures. It's been my experience that it is probably the best monitoring tool out there. Another good one is HWinfo. Both report temps exactly the same.

For whats its worth, I was still typing when you posted that. I couldn't find that darn info thread. Cheers
cheers.gif
 
Quote:
Originally Posted by Jodo Kast View Post

[IMG
So what should I say my load temp is? 49c?
Yes. So that gives you 10° of overclocking headroom. Bump the multiplier a step, and stress test for 5 minutes. If it doesnt crash, and your temps are fine, bump it another step and repeat the process over and over again till you either crash or start getting too hot. If you crash, then bump the voltage up until its stable. Of you get too hot, get another cooler.
 
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