E8400 Temps Question

[lurker316]

I just finished Installing an E8400 cpu on a Asus P5E-VM-HDMI uatx board in a Thermaltake VF1000BWS Lanbox SFF case.

Initially when I was running on an old Bios, Asus's Probe Utility and bios were reporting CPU temps @ 3C idle! The Mobo temps were at 39C.

I flashed the Bios to newest version and the CPU temps were now being reported by Bios and Asus Probe utility at 32C Idle. Mobo temps are still 39C.

However Coretemp is showing both cores at 45C idle.
I have not overclocked anything and am using the stock Intel cooler.

Whats up with this large temperature discrepancy? And do you people think its a tad bit too hot to run idle @45C for this processor?

 

[UtopiA]

Ignore ASUS Probe.
Only use Core Temp.

45C is fine for idle temp, what needs to concern you is your load temp. Run Prime95 for a while and watch the temps.

[edit]
btw what is your ambient?
45C seems pretty hot for stock settings. Do you have that Intel fan control crap enabled (makes your fan run at 900 RPM idle, or so)? That would cause some hot temps if the fan is running slow.
Then again maybe you mounted the HSF wrong.

Though I'm not that familiar with average E8400 temps, so...

 

[M.D.Geist]

Core temp will also report the temps quite off (at least from what was seen with other e8400 owners) And if you are using vista, I believe you'll have to do some minor changes to get it to work. There was a temperature discussion around [H] about the e8400's having different temps. Should still be around ^^ You also might want to try to google it, as many popular forums have gone over this. Lots of good reading for you to check up on the e8400.

A friend of mine posted this http://www.guamserver.com/gsforum/showthread.php?t=3447&highlight=real+temp

Original thread starter of the program is found here.
http://www.xtremesystems.org/forums/showthread.php?t=179044

Pretty accurate program and it works just fine on vista 64 ultimate.

I live on Guam and it gets quite hot over here. I was experiencing weird temp readings as well. The Asus monitoring tools would read my e8400 with a stock cooler at around 25C and sometimes it would just jump to 34C for a few seconds to as long as 30 and back to 25C (mind you this is with the computer on idle, not running any apps).

I do have a good air flow in my rig, so my temps are not so high. That could also be why your temps are up there.

 

[crawford60]

Yeah that seems high. My E8400 is at stock speeds, and using stock heatsink (but with Arctic Silver 5) and it idles at 27-28C, and maxes out at 50C under full load. You should try reseting the heatsink, to see if that will help.

 

[M.D.Geist]

Hey, found the original thread ^^ http://www.hardforum.com/showthread.php?t=1268214&highlight=e8400

Yes, reseating the stock hsf would be a good idea. Also, get yourself some AS5 or MX-2 paste and it'll really help drop your temps ^^

Also, if you are planning to oc, it would be in your best interest to invest in an aftermarket cooler. I'm currently using a ThermalRight Ultra 120 Extreme with two 120mm fans that push 110cfm of air and it's keeping my cpu nicely cooled

 

[lurker316]

I Just removed the Stock HSF and re-oriented it... The temps are still the same. No Change at all.
Ofcourse I am not using Arctic silver or any other after market paste, just whatever that came with the Stock HSF.

I even droped the Vcore down to the lowest possible setting of 1.100. Still no change.
But Once I run Prime95 the Load temps jump to 53C. More over, I think there is something wrong with CoreTemp, since even when Speedstep reduces the clock to 2Ghz, the temps stay the same.

 

[UtopiA]

You just took the HSF off, then put it back on? You didn't change the paste?
You shouldn't do that. I'd go order some AS5 right now, anyway, it's only like $6.

Besides you need to put new paste on there now!

Temps are independent of clock setting. It's your vcore that determines the temp.
When the multiplier drops (C1E), see if it lowers the vcore. At stock settings, my C1E lowers the vcore too. But as soon as I set a MANUAL vcore, C1E doesn't lower the vcore anymore.

You've set a manual vcore of 1.1v, thus C1E won't do anything for your temps at all.
Your manual vcore setting prevents the vcore from dropping during idle. So your vcore now stays the same, and your temps won't drop because of that. However your clock settings (multiplier) will still drop.

 

[Autochthon]

I'm running a very similar setup in a tiny little antec1380. It runs quite warm. With stock cooler running @ 3600 under full load it would jump up 78C (50C above ambient) for cpu and 75C for cpu core 0 (as measured by real temp 2.24). I put the biggest after-market cooler that would fit in the case (not very big, and I had to shave a bit off of the fan shroud to even get it to fit at all) and it now runs at least 10C cooler under full load. Still too hot by my reckoning but then I'm cramming quite a lot into a very small space

 

[lurker316]

You just took the HSF off, then put it back on? You didn't change the paste?
You shouldn't do that. I'd go order some AS5 right now, anyway, it's only like $6.

Besides you need to put new paste on there now!

Alright, I cleaned up all the original Intel thermal goo and put some AS5 on it. Re-seated the stock HSF and Coretemp still shows 45 at boot and idle. These thermal Diodes are killing me.

 

[tenub]

Do what UtopiA suggested at the end of his post.

 

[-=Antimatter=-]

Use Real Temp, not Core Temp.

 

[matt_man22]

Alright, I cleaned up all the original Intel thermal goo and put some AS5 on it. Re-seated the stock HSF and Coretemp still shows 45 at boot and idle. These thermal Diodes are killing me.

I think unclewebb, who does a lot of testing with these chips, says to not worry about idle temps, just worry about the load temps.

My e8400 idles at 46c with a Zerotherm Nirvana. However, at stock it's load is only around 52c under CoreTemp, and 42C under RealTemp. The temperatures may very well not be accurate at idle, since they only have to be correct at high temperatures.

 

[UtopiA]

What is "Real Temp"? Why have I never heard of it, why are people using it, and why is it more accurate than Core Temp?

RealTemp is showing my Tjunction Max at 95C, when it is 100C.

B3, G0, L2 Stepping = Tjunction Max 100c

Thus, RealTemp is off by 5 degrees.
CoreTemp is showing 100C Tjunction Max, and is showing 5C hotter than RealTemp.

Know your Tjunction Max, and use the program that shows the correct value.
Here is a complete TMax table:

B2, M0 Stepping = Tjunction Max 85c
B3, G0, L2 Stepping = Tjunction Max 100c
C0, C1, M1 Stepping = Tjunction Max 105c

If my TMax is REALLY 95C, then RealTemp is showing the correct temp.
Intel states that the TMax can change for certain processors, so RealTemp might be showing more accurate temps. Then again, every Q6600 G0 owner is reporting 95C Tmax in RealTemp, which seems odd.

Saw some people do manual tests for TMax and they reported that RealTemp is showing the correct TMax.

 

[lurker316]

I do not have a problem with Load Temps. They average around 53C on Stock Intel cooler at Stock settings. The problem is that Idle NEVER goes below 45C. It seems like it'll never drop even if you used Liquid Nitrogen!

 

[UtopiA]

Idle temps don't matter.

 

[matt_man22]

What is "Real Temp"? Why have I never heard of it, why are people using it, and why is it more accurate than Core Temp?

It is not more accurate since it takes the same reading from the chip, but the author of the software tried to use real world tests to figure out the TjMax.

Here is what he said:

Intel does not publicly document what TjMax is for desktop processors. TjMax is fully documented for their Mobile processors but not for their desktop Core processors. Without this reference point, your absolute temperature data could be meaningless. Intel has also confirmed that there is no secret bit hidden in these chips that a programmer can read to determine what TjMax really is. The only thing a programmer can do is guess at TjMax and if he gets lucky and the reported temps look more or less believable then everyone is happy.

 

[delvryboy]

Real temp was made around the e8xxx processors. If you're using a Q6600, use core temp.

 

[Lames.]

Idle temps don't matter.

To some of us paranoid people it does. When I was toying with my 8400 and was getting weird idle temps, it bothered me because my 6750 was OCed to 3.2ish and sat 20c idle.

 

[lurker316]

It is not more accurate since it takes the same reading from the chip, but the author of the software tried to use real world tests to figure out the TjMax.

According to the Coretemp Author:
Intel defines a certain Tjunction temperature for the processor. In the case of Yonah it is 85C° or 100C°. First of all the program reads from a Model Specific Register (or MSR), and detects the Tjunction temperature. A different MSR contains the temperature data, this data is represented as 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 - 127C° can be reported in theory. But from preliminary tests, the reported temperature doesn't go below 0C°, no matter what kind of cooling was used.