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E8400 CPU Temps Summertime

  • CPUs
  • Cooling
Last response: in CPUs
May 1, 2009 4:03:21 AM

Wondering if the following temps were a reason to be concerned under my conditions.

Was running Prime 95 and got these max temps for an E8400 C0 Processor with the following cooler

using Real Temp 3.00 Uncalibrated:

Core0: 61C Full Load
Core1: 60C Full Load

Using Rivatuner 2.24 with Core2Duo Plug In:

Core0: 60C Full Load
Core1: 60C Full Load

Using Gigabyte Easy Tune Monitor

CPU: 55C Full Load
System: 36C

Ambient room temp is around 28-29C

Touched cooler and it is not even warm to the touch.

Antec 900 case fans set to medium

In wintertime these temps were 8-10C cooler.

Just wondering if these CPU were anything to be concerned about since it is sorta warm in the room?

Should i try to reseat cooler? Has been a year since install?

How tight should spring screws be on cooler/motherboard?

Any suggestions/comments would be appreciated.

Please help me gain Peace Of Mind!!!!!

More about : e8400 cpu temps summertime

May 1, 2009 5:27:32 AM


Your temps look fine no need for concern.
a b à CPUs
May 1, 2009 6:02:08 AM

I've had my e8400 for over a year. Your temps are very close to mine. If you want to see slightly cooler temps, leave the side panel out and blow a small quiet deskfan into the motherboard.
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a c 173 à CPUs
May 1, 2009 8:35:27 AM

Your temps are fine. The spring screws should be all the way down and snug, but not supertight.

I also suggest that you set the thermal alarm to 70 C. in the motherboard BIOS.
a c 309 à CPUs
May 1, 2009 9:36:10 AM


Intel's Thermal Specification for your E8400 C0 is 72C, which is maximum CPU temperature (Tcase Max), NOT maximum Core temperature (Tjunction Max). The specs are shown in the Processor Spec Finder:

Since Core temperatures are 5c higher than CPU temperature, the corresponding Core temperature is 77c, regardless of the fact that Tjunction Max is 100c, which is shutdown temperature, and is far too hot for sane operation.

The 5c relationship between CPU temperature and Core temperature is shown in the following Intel document:

CPU temperatures which exceed 72c and Core temperatures which exceed 77c should be considered an "overtemp" condition.

For detailed information regarding processor temperatures, check out the Core i7 and Core 2 Temperature Guide:

From the Guide:

Scale 2: Duo
E8x00: Tcase Max 74c, Stepping E0, TDP 65W, Idle 8W
E7x00: Tcase Max 74c, Stepping R0, TDP 65W, Idle 8W
E7x00: Tcase Max 74c, Stepping M0, TDP 65W, Idle 8W
E5x00: Tcase Max 74c, Stepping R0, TDP 65W, Idle 8W
E5200: Tcase Max 74c, Stepping M0, TDP 65W, Idle 8W
E4700: Tcase Max 73c, Stepping G0, TDP 65W, Idle 8W
E4x00: Tcase Max 73c, Stepping M0, TDP 65W, Idle 8W
E2xx0: Tcase Max 73c, Stepping M0, TDP 65W, Idle 8W
E8600: Tcase Max 72c, Stepping E0, TDP 65W, Idle 8W
E8xx0: Tcase Max 72c, Stepping C0, TDP 65W, Idle 8W<--E8400 C0
E6x50: Tcase Max 72c, Stepping G0, TDP 65W, Idle 8W
E6540: Tcase Max 72c, Stepping G0, TDP 65W, Idle 8W

--70--/--75--75-- Hot
--65--/--70--70-- Warm
--60--/--65--65--Safe <--
--25--/--30--30-- Cool

Your temperatures are well within Intel's Thermal Specifications, so relax and enjoy your rig!

Comp :sol: 
May 1, 2009 2:21:24 PM

Which cooler are you using? In my mind, if the cooler is not even warm, how much heat could it be taking away from the CPU? I wouldn't be suprised if you could lower those temps significantly with a different cooler.
a c 309 à CPUs
May 1, 2009 7:29:19 PM


A thermal gradient of ~ 30c exists between the heat source (cores) and the CPU cooler components, such as the heat pipes and fins, which may typically only feel warm to the touch, even when the processor is at 100% workload with Prime95 Small FFT's and Core temperatures are at 60c. This is normal and expected, so it is not possible to accurately evaluate CPU cooler performance just by "touch".

Under the conditions decribed above, since goatfarmer's CPU temperature is 55c and Core temperatures are 60c, which shows the corredct 5c thermal relationship, I believe his uncalibrated temperatures are fairly accurate. Further, as I've already shown in my previous post that his temperatures are well within Intel's Thermal Specifications, I see no problems here.

Comp :sol: 
May 2, 2009 11:48:22 PM

Thanks for all the help and suggestions all! Problem has been solved. While I feel kinda stupid and a noob, and am debating whether or not to admit what I did wrong, I guess I will.

#1 - Poor application of thermal compoud. Not a good contact area on cooler.

#2 - There was a clear piece of protective plastic over the base of my heatsink that was pretty much impossible to see when I installed the cooler. Most things have a blue colored protective sheet that I have seen. This one was clear, and was the exact size of the cooler contact plate. So............the past year I have had a piece of plastic between my CPU and CPU cooler, and it was still giving me the aforementioned temps. Not bad considering the cooler was not doing much. I have since reinstalled the CPU cooler and am getting temps 15-20C cooler.

I feel like I have wasted some people's time with this post, but it is much appreciated. Maybe someone building a computer in the future will read this and it will pop in there head to check for that protective plastic, hence why I am admitting my stupidity. All I can say is "DOH" and just pay minute attention to everything in the future. LOL! Thanks again for all those that helped!