Page 1 of 1

CPU or Core Temps

Posted: 01 Jun 2010, 20:49
by CranialBlaze
Image

This is something that really confuses me, i have tried google but as i am not sure exactly what to search for i have not yet found an actual answer.

What temperature do i need to actually worry about, the temp in the BIOS matches that of the "CPU" temp, but now the "Core 1" temp is almost double that and i know danger zone is around 75 for the Q8300 and in testing the Core temps easily hit 70, but then the CPU is only around 40/45.

I just put on a much better cooler it dropped the CPU temp from 31 idle to now 20 idle but the core temps have remained the exact same as before.

I would like to OC this CPU, i know it can handle up to 3.6, i have tested it that far but the temps made me rather not, now with a better cooler i only see 1 reading change and just what to know which is the reading i really need to concern myself with when pushing the living hell out of this thing.

Thanks guys

This is something that really confuses me, i have tried google but as i am not sure exactly what to search for i have not yet found an actual answer.
What temperature do i need to actually worry about, the temp in the BIOS matches that of the "CPU" temp, but now the "Core 1" temp is almost double that and i know danger zone is around 75 for the Q8300 and in testing the Core temps easily hit 70, but then the CPU is only around 40/45.
I just put on a much better cooler it dropped the CPU temp from 31 idle to now 20 idle but the core temps have remained the exact same as before.
I would like to OC this CPU, i know it can handle up to 3.6, i have tested it that far but the temps made me rather not, now with a better cooler i only see 1 reading change and just what to know which is the reading i really need to concern myself with when pushing the living hell out of this thing.
Thanks guys

Re: CPU or Core Temps

Posted: 01 Jun 2010, 21:07
by R3D
you should look at the temps of the cores. Not the "CPU: one
That temps is irrelevant seeing as the core temperature is what you want to know.
The CPU probe is not located on a important heat spot of the CPU thus it being irrelevant.

Re: CPU or Core Temps

Posted: 01 Jun 2010, 22:25
by Prime
Check your heatsink is on properly and definately hook it up with some decent thermal compound. Beyond that, it's entirely possible you have a faulty sensor on your board or processor. My Q9300 is like that.

Re: CPU or Core Temps

Posted: 01 Jun 2010, 22:30
by CranialBlaze
Prime wrote:Check your heatsink is on properly and definately hook it up with some decent thermal compound. Beyond that, it's entirely possible you have a faulty sensor on your board or processor. My Q9300 is like that.
I just set the sink on this evening, i know its on properly and i use Zalman STG1. I just ran RealTemp with prime 95 and the idle temps may be identical to that of my old sink but the load temps are way better, from ~70 to <50, as long as the load temps are good i suppose i can ignore the idle ones.

Re: CPU or Core Temps

Posted: 01 Jun 2010, 22:35
by Prime
CranialBlaze wrote:
Prime wrote:Check your heatsink is on properly and definately hook it up with some decent thermal compound. Beyond that, it's entirely possible you have a faulty sensor on your board or processor. My Q9300 is like that.
I just set the sink on this evening, i know its on properly and i use Zalman STG1. I just ran RealTemp with prime 95 and the idle temps may be identical to that of my old sink but the load temps are way better, from ~70 to <50, as long as the load temps are good i suppose i can ignore the idle ones.
Yeah, I am using that too. It's good stuff :)

Re: CPU or Core Temps

Posted: 03 Jun 2010, 10:11
by IcePick88
R3D wrote:you should look at the temps of the cores. Not the "CPU: one
That temps is irrelevant seeing as the core temperature is what you want to know.
The CPU probe is not located on a important heat spot of the CPU thus it being irrelevant.
I tend to disagree.

When Intel or AMD tells their customer that the max temp for the chip is for example 70'C, then they are referring to the CPU temp and not the core temps.

Core temps are calculations:
Intel defines a certain Tjunction temperature for the processor. This value is usually in the range between 85°C and 105°C. In the later generation of processors, starting with Nehalem, the exact Tjunction Max value is available for software to read in an MSR (short for Model Specific Register).
A different MSR contains the temperature data. The data is represented as a Delta in °C between current temperature and Tjunction.

So the actual temperature is calculated like this 'Core Temp = Tjunction - Delta'

The size of the data field is 7 bits. This means a Delta of 0 - 127°C can be reported in theory. In fact the reported temperature can rarily go below 0°C and in some cases (Core 2 - 45nm series) temperatures below 30° or even 40°C are not reported.
http://www.alcpu.com/CoreTemp/howitworks.html

Because of this, core temps are not really very reliable. I say, stick to the overall CPU temp and don't worry too much about the core temps. If your cores are running at 90'C but your CPU temp stays within the manufacturers specifications, you are OK.

Re: CPU or Core Temps

Posted: 03 Jun 2010, 22:53
by R3D
IcePick88 are you stoned off your balls or something?

The most important part of a CPU is the cores ergo the temps of said cores are what you need to worry about.

I suspect you have never killed a CPU before? I have. tested temp tolerances on an E8600. at 4.8ghz running P95 it was alive till 110deg at which point it died. That was the core temp not the CPU temp. CPU temp was at 75deg (If i remember correctly) well within intel specs.

Re: CPU or Core Temps

Posted: 04 Jun 2010, 08:14
by IcePick88
R3D wrote:IcePick88 are you stoned off your balls or something?

The most important part of a CPU is the cores ergo the temps of said cores are what you need to worry about.

I suspect you have never killed a CPU before? I have. tested temp tolerances on an E8600. at 4.8ghz running P95 it was alive till 110deg at which point it died. That was the core temp not the CPU temp. CPU temp was at 75deg (If i remember correctly) well within intel specs.
I scoured the net searching for concrete evidence from either AMD or Intel to say which is best to monitor. CPU temp or core temps but I have found nothing.

I have had a couple of cpu's, but no-where on the box or in the manual or in papers on the net does it say to monitor the core temps. Only to download the manufacturer of the motherboards monitoring software and monitor the temps there, and I strongly believe it monitors the CPU temp and not the cores. The individual core temps threw a spanner in the works for computer hypochondriacs. Now there is even more things to worry about! NO! :shock:

So for now, until there is concrete evidence from the manufacturers, all this is hearsay and opinions and should not be taken for fact.

Re: CPU or Core Temps

Posted: 04 Jun 2010, 09:03
by CranialBlaze
IcePick88 wrote:
R3D wrote:IcePick88 are you stoned off your balls or something?

The most important part of a CPU is the cores ergo the temps of said cores are what you need to worry about.

I suspect you have never killed a CPU before? I have. tested temp tolerances on an E8600. at 4.8ghz running P95 it was alive till 110deg at which point it died. That was the core temp not the CPU temp. CPU temp was at 75deg (If i remember correctly) well within intel specs.
I scoured the net searching for concrete evidence from either AMD or Intel to say which is best to monitor. CPU temp or core temps but I have found nothing.

I have had a couple of cpu's, but no-where on the box or in the manual or in papers on the net does it say to monitor the core temps. Only to download the manufacturer of the motherboards monitoring software and monitor the temps there, and I strongly believe it monitors the CPU temp and not the cores. The individual core temps threw a spanner in the works for computer hypochondriacs. Now there is even more things to worry about! NO! :shock:

So for now, until there is concrete evidence from the manufacturers, all this is hearsay and opinions and should not be taken for fact.
I myself also did some serious searching and never thought i would need to save the links, but the hard irrefutable information does exist online, there is a common problem that mainly affects Intel quad core chips. The thermal sensors on the quad cores are actually out by 15 degrees Celsius, i am not sure about dual cores as i don't own 1 and don't really care, so if your cpu temp reads as 20 degrees then the actual temp would be 35 degrees putting its temp much closer to those of the core temps, the only way to improve the accuracy and lessen the gap there is to lap the CPU and Sink, after that the difference between the CPU as well as the Core temps with the error margin calculated would be no more than 3 degrees.

If i find those sites again i will most the links, but i got a load of work ahead of me so i probably won't bother looking any time soon.

The most accurate way to get the true "CPU" temp would be 1 of those wafer thermal sensors similar to the ones that are shipped with the Odin PSU's even those specifically wont work you can get the higher quality ones online, i found them on ebay, if you get the wafer thin ones you can actually get them in between the HSF and CPU without any negative effects.

Re: CPU or Core Temps

Posted: 05 Jun 2010, 01:35
by ADV4NCED
R3D is actually correct, stick with monitoring the cores and you wont go wrong.

The cores are always hotter than the 'overall cpu reading' - this way its safe to go according to the core temps, rather than the overall cpu value.

As you mentioned that cpu value is always inconsistent with what the real temp actually is.

Check core temp, there's a reason it displays the individual core temps and not the 'overall temp' that the bios reads....

Re: CPU or Core Temps

Posted: 05 Jun 2010, 18:48
by 1gn1t0r
Check your heatsink

Re: CPU or Core Temps

Posted: 07 Jun 2010, 08:46
by IcePick88
Ok, so I monitored my core temps in relation to my cpu temp and I found that my cores are running cooler than the cpu temp. :?:

On idle, my cpu temp is something like 31'C and my cores are running between 21'C and 25'C.
When I run Prime95, the ratio stays the same.