CPU temperature wrong?

[kiranatwo]

My new superpc W7 build is up and running. Wow, exciting for a novice 85-year-old builder and what an improvement over my old XP.

However, I am getting conflicting information re my CPU temperature. The reading from the Settings tab in the BIOS shows 81 degrees C and a color bar ranging left to right from green up to orange. Worried earlier about slightly higher readings, I shut down, removed the CPU cooler, cleaned up the old thermal grease with alcohol and replaced same with new Arctic Silver. Grease pattern is good, cooler mounts are secure and solid, all fans running fine, but the temp result is the same.

I downloaded an app named Real Temp from Techpowerup.com and ran it. This gives temps for each of the 4 cores in the i5 and shows readings of 30-34 C for each. Who to believe?? While the MSi motherboard BIOS temp number is dangerously high, I note that it is almost the F numerical equivalent of the C reading shown by Real Temp. Anyone else have a similar experience with the MSi motherboard?

I’m also puzzled by why the Intel CPU retail package includes a circular heat sink surface on the cooler whereas the CPU matching surface is square. That’s a loss of over 20% in total potential heat transfer surface.

Should I worry about the temps or assume that they’re OK?

Thanks.

Fred T
Power supply: Antec Sonata III; 500-Watt power supply; CPU: Intel Core i5-2500K 3.3GHz; Mainboard: MSI P67A-GD65(B3) LGA 1155: RAM: Kingston HyperX Blu 8GB Kit (2x4GB) PC3-10600 DDR3; Video: EVGA GeForce GTX 560 Superclocked 1GB DDR5; HDD: Western Digital Caviar Green 2TB 7200rpm SATA 3; DVD: Sony 24x SATA DVD RW/CDRW; Keyboard / Mouse: Logitech MK 520 (Keyboard and Laser Mouse); Monitor: Viewsonic 24-Inch Widescreen LED Monitor Full HD 1080p; Windows 7 Home Premium SP1 64-Bit

[zburns]

With the BIOS showing 81 degrees, are you reading the heatsink, one core, two or four cores, etc.

One way is this way: Let the computer cool off. Let the Temps get as low as possible. Run multiple readings starting with the computer almost cold. Turn it on, wait 30 seconds, take readings at 1 minute, 5, 10 and 15. Convert the BIOS readings to C and compare. If they match, your assumption is correct. If you are not right, the differences will stand out.

Intel can probably prove that a circular heat sink is more efficient than a rectangular. I will try to 'google' it later and find out.

My temp solution was written fast; if any more explanation needed, post back to the forum.

[kiranatwo]

Hello again, zburns, and thanks for the response. Re your comments…

There is no indication where the BIOS reading is being taken, other than ‘CPU temp in degrees C and the temperature bar graphic. Elsewhere in the BIOS menu under ‘Overclocking’ I discovered another listing that again shows the same CPU temperature, with an additional reading showing ‘System Temp’ at 32 degrees C.

This latter temp is in the range of the individual Centigrade core temps shown on the Real Temp application display I mentioned. The actual values are constantly varying but the app also shows min and max histories as below:

Centigrade core 1 core 2 core 3 core 4
actual 35 36 34 37
min 32 35 34 33
max 43 47 45 46

My conversion to F…

Fahrenheit core 1 core 2 core 3 core 4
actual 95 97 91 99
min 90 95 93 91
max 109 117 113 115

As you suggested, I took the MSI BIOS temperature readings at intervals after startup. Startup was 12 hours after shutdown so everything should have been at room ambient:

CPU Temperature per MSI BIOS
( room ambient temp at start = 68F (20C)
Elapsed time from boot (minutes) Readout in Degrees Centigrade Conversion to Degrees Fahrenheit
0.5 61 142
1 70 158
5 82 180
10 86 187
15 88 190

System Temperature per MSI BIOS = 32C (90F)

Pretty rapid rise to the high 80s and thereafter steady, fluctuating between 87 and 89C.

These are readings when the CPU isn’t being asked to do much as I haven’t loaded any apps yet.

So z, do you think I should worry about these temps or just move on?

Thanks again,

Fred T

[ARchamps]

Using the Celcius numbers, those look normal for idle temps. What are you temps under 100% load? You can test this with a stress test (ie. prime95).

[zburns]

kiranatwo

I apologize for this late reply. Unavailable most of yesterday. You would think there would be a simple answer to your questions. I am looking for such. Here is the best I have found so far -- fortunately, it is an Intel website. Not sure it really gives you a good answer, but there does seem to be a lot of confusion. Here's the link: http://communities.intel.com/thread/23136

In additon to the Intel post, here is one about Real Temp -- the author should write for the Britannica folks: http://www.techpowerup.com/realtemp/

What I was looking for is some 'definitive' answer as compared to a lot of random 'this is it' statements.

I will keep looking but I thought you might be interested in these links. Your 80 degree temps bother me; however, the cpu chip has to have temp cutout sensors in it which would be shutting you down. In addition, one would think that if you were overheating, even random internet searches on google would 'act up'!
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Here is another link, better info than above: http://communities.intel.com/message/129008
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Be back later. Have to read the various stuff myself, think about it, etc..

[zburns]

What kind of cooler do you have sitting on the cpu?

[zburns]

kiranatwo,

Here is a link for temps on the i5 2500k cpu. The person doing the work has a lot of experience and the single page says a lot. Here is the link: http://www.tomshardware.com/forum/308697-28-2600k-heatsink-cooler-temperature-thread

His voltage for the i5 2500k is vcore @ 1.18. His speed (frequency) is stock speed, no overclock.
If your voltage is set a lot higher, this would explain the high temps, maybe. Also, on this page is a warning about how to shorten the cpu life; and it is about running Vcore too high.

I also suggest you check you Vcore voltage on the cpu. You would look in the BIOS under Hardware, then cpu and you should see voltage. I caution you to go easy doing this. You can permanently damage the cpu by getting the voltage to high. Why not just look at the voltage in the cpu and get back on the forum. You might also look in your motherboard instruction booklet and see what it says in the BIOS about cpu voltage, etc..

The above comments are fine. It just occurred to me that I can pull up your motherboard manual and take a look for myself. It will be in the morning at the earliest, but I should do a post back by late am or mid afternoon, latest.

You do not have hyperthreading so that means the i5 2500k will have less stress, therefore, less heat, lower temp, etc.. -- compared to the i7 2600k.