Core Vs. CPU Temp for AM3(+) cpus

[prudhomb]

I just installed my antec 620 so Im finally able to push the volts a little further, I put in 1.4v, my core temps were in the low 50's but my cpu temp reached nearly 70c.

Ive never had that much of a difference before, it concerned me so I stopped running prime.


Is that just some sort of weird sensor on the board???

Am I ok as long as the core temps are lower??

with a max temp of 62c I was a little concerned.


I was wondering what kind of temps others were getting with their x6's


Edit--

copying info from Mr.Scott and AMD to top of thread for quicker reference, with a title change to make it more search friendly.

Quote:

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

[Carozzeria]

What programs are you using?
I've noticed that CoreTemp reads a 16C deviation between two cores on my 5200+ but all of the other programs show normal readings. Try AIDA64 or Speedfan and see if the readouts are still high. 70C doesn't sound right even for 1.4...

[moosteve]

Originally Posted by prudhomb

I just installed my antec 620 so Im finally able to push the volts a little further, I put in 1.4v, my core temps were in the low 50's but my cpu temp reached nearly 70c.

Ive never had that much of a difference before, it concerned me so I stopped running prime.


Is that just some sort of weird sensor on the board???

Am I ok as long as the core temps are lower??

with a max temp of 62c I was a little concerned.


I was wondering what kind of temps others were getting with their x6's

all i have ever been taught here at the Forums is its the CPU temp you want, not the cores.
i assume you have reseated already, and perhaps played with fan direction?

[Mr.Scott]

The hexcores run hot. I told you the 620 wasn't enough cooler.

[prudhomb]

Its better than my hyper 212+, but

Ive never seen such a huge variation between core and cpu temp, up to this point they have always been in the same neighborhood.

Additional Comment:

something is fishy,

at idle my cpu temp is 40c, and my core temp is 25.

my 620 arrived with out a amd backplate, but on inspection it looked just like the back plate that comes with the board (minus the top bracket so I used it) cooler seems pretty snug. I guess Ill reseat today.

something is strange

[moosteve]

Originally Posted by prudhomb

Its better than my hyper 212+, but

Ive never seen such a huge variation between core and cpu temp, up to this point they have always been in the same neighborhood.

Additional Comment:

something is fishy,

at idle my cpu temp is 40c, and my core temp is 25.

my 620 arrived with out a amd backplate, but on inspection it looked just like the back plate that comes with the board (minus the top bracket so I used it) cooler seems pretty snug. I guess Ill reseat today.

something is strange

that is the way my Bulldozer, and my 1090T read. right now my FX6100 is 32 cpu, and 16 cores.

my waterblock is fine, but with the backplate/mount on my Prlimatech, i added small washers to increase pressure on the cpu to get a tighter mount (like the old True penny mod).... stock, the Megahalems was a little bit too loose.

[prudhomb]

Originally Posted by moosteve

that is the way my Bulldozer, and my 1090T read. right now my FX6100 is 32 cpu, and 16 cores.

are you talking about the pressure or the diffrence in temps??

at anyrate, I discovered why I couldn't use my H70 AMD backpalte, it was missing the pins that were supposed to go in there as well (even for the intel plate) Im sending it back to amazon, I be leave they are letting me keep the $5 credit.

the price of a new one dropped $6, and with the credit, it is actually going to be the same price as a new one.

[moosteve]

Originally Posted by prudhomb

are you talking about the pressure or the diffrence in temps??

at anyrate, I discovered why I couldn't use my H70 AMD backpalte, it was missing the pins that were supposed to go in there as well (even for the intel plate) Im sending it back to amazon, I be leave they are letting me keep the $5 credit.

the price of a new one dropped $6, and with the credit, it is actually going to be the same price as a new one.

temps.... CPU 32C, cores 16C.

the washers are for pressure on the cpu IHS.

[prudhomb]

Originally Posted by moosteve

temps.... CPU 32C, cores 16C.

the washers are for pressure on the cpu IHS.

which do you use to monitor the cpu temp??

[Nagoshi]

Originally Posted by prudhomb

which do you use to monitor the cpu temp??

The hottest, for safety.

AMD always had issues with temperature readings since AM2.

[prudhomb]

at least at idle the core temps make more sense. Im not sure how with an all in one cooler (though i might have it installed incorrectly due to my bracket issue) that at 1.35v it would lidel at 40c.

[Carozzeria]

Is your ambient temperature about 27c?

[prudhomb]

its probably 24-25 in the house, which is about what my cores are idling at.

[ShrimpBrime]

Try putting a fan near the mosfets and nb if not already. See if the cpu temp drops.

[Mr.Scott]

AMD tells you flat out that their temps are not correct below 40c, so don't even look at an idle temp. Load it and see how it goes.

[ShrimpBrime]

Originally Posted by Mr.Scott

AMD tells you flat out that their temps are not correct below 40c, so don't even look at an idle temp. Load it and see how it goes.

Never seen a problem when using Dry Ice. Was within 10c or so @ -40c

[Mr.Scott]

I'm just sayin'......

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

[ShrimpBrime]

Phenom II = Colder is better. No argument there.

[prudhomb]

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.

Hmmm, it seems to this if my core temps are in the low-mid 50's Im allright

Additional Comment:

In general I like to keep my core temp below 55

[FunkZ]

Originally Posted by Nagoshi

AMD always had issues with temperature readings since AM2.

Agreed. I've noticed a wide variance between chips DTS going back as far as Venice. They always read lower, sometimes by as much as 10-15°C, than the motherboard CPU temp. This is confirmed by the author of CoreTemp.

Ex. my 1090T is showing 13°C in CoreTemp right now. Impossible as my ambient is ~22-23°C. The motherboard CPU sensor reads 24°C. All of the onboard thermal controls use the CPU temp anyway so the DTS CoreTemp is pretty much useless.

CoreTemp will not display a value <0 and according to the author it's because the DTS will not report a less than null value. Most motherboard CPU temp will display a negative temp though.