BIOS vs. "Core Temp" temperatures

Hey guys,

So I picked up a machine for $100 with an AMD Phenom 840.

The BIOS reads 30-36*C booting anew and 50-60*C after running a game on high settings for a hour and then rebooting.

The program "Core Temp" has me idling at 65-70*C and up to 90*C on high load (and the max of this thing is apparently 70*C). It says I'm at 74*C just browsing the web.

How do I decide which to trust?
10 answers Last reply
More about bios core temp temperatures
  1. BIOS Temps are the most accurate, however your CPU is not idling when you are in it. I really don't know how you measured load though.

    Have you tried a different program like HW monitor?
  2. Coretemp isnt good with older AMDs. Get HWinfo64 or HWmonitor.

    BIOS is accurate. Sometimes coretemp requires you to manually offset the temps.
  3. HWmonitor has me at ~38*C browsing the web for "CPU" temperature.

    But below the AMD Phenom area each of the cores is listed at 63*C.
  4. Ahh now its coming back to me. I had a 840 once and it gave me some weird information too. I think you'll be fine, if your CPU was really over 70C then your PC would shut down in thermal protection. What do you use for cooling?
  5. It's the stock cooler which is why I was concerned.
  6. Download OCCT:

    Run the CPU stress test and report back with screenshots during the load. OCCT has all the sensors built in too so you can use the one program for stress testing and monitoring.
  7. I ran it and here are the results:

    Just started:
    One minute in:
    One minute and 25 seconds resulted in an error:

    Updated with higher res pictures so you can actually read it.

    This shows the CPU temp being fine. I just can't tell if the cores are the actual CPU temperature and the CPU temperature listed is actually my case temperature. I've never had a processor with more than a single core before.
  8. Reduce CPU voltage to 1.35, remove CPU cooler clean paste off of CPU and the cooler with isopropyl alcohol and paper towel or coffee filters. Then apply fresh paste and make sure the cooler is mounted correctly. If the temps are still off its probably an inaccurate reading. Biostars are known to have problems with 3rd party software. Does biostar have a utility you can use?
  9. Will do, thanks! So those core temps are my actual CPU temp and the CPU temp listed is my case? Or do the cores just run hotter than the CPU as a whole?

    I'll update tomorrow with another test run after I've reseated the heatsink and lowered the voltage.

    Biostar does not seem to have any utility (I looked prior and only found some stupid remote thing that I can't figure out the use of).
  10. So after reseating, cleaning out the case a bit, and dropping the voltage the temps dropped a little but not much.

    However, I believe they are fine. What I was supposed to be looking at is the tag labeled "CPU Temp". I found statements from AMD that say the "Core Temps" are values that aren't actually measuring temperature.

    It may be helpful to quite a few here as I've seen the issue come up a lot in search results:


    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.
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