Weird E7500 temp behaviour

Hello people, first post in tomshardware forums :D ,

Here's my issue: until a couple of months ago I was using a core 2 duo model E4400 (2.ghz) in an intel motherboard. Since I wanted to overclock the E4400 and the intelmobo didn't allow me to do that, I bought a new motherboard, an asrock G31M-S (the box says it's a G31M-S R2.0, but the BIOS says it's just a G31M-S). So, I tried several times to OC the E4400 bbut I couldn't because the temperature were always high; even with a freezer xtreme cooler it rarely went under 42 ºC idle and could reach more than 60 ºC at full load (without overclocking). Then I decided to buy a new cpu, an C2D E7500 (2,93 ghz), and replaced the old E4400 for this one, on the same board. The weird thing now is when I enter the BIOS, the temperature goes to 48 - 50 ºC in about 5 minutes (mobo temperature is about 36 ºC generally), but everything else I use to measure the temperature gives 38 ºC idle, either on windos or linux (core temp, real temp, speed fan, lm-sensors, etc.), but if I run some stress program like orthos, prime95, etc, it easily reaches 75 ºC in about 2 minutes and keeps getting higher, so I have to stop it.

As a side note, I haven't overclocked this cpu yet,and I'm using it with the stock cooler. Also, the first time I installed the cooler it didn't adjust fine,so I had to take it out, clean it as well as the cpu, and apply some thermal grease before reinstalling it (thermaltake tg-2m to be specific). The case I'm using is not a very good one, and doesn't have good ventilation, but I took out one of the side panels and put a 8 cm fan at the rear, so there shouldn't be serious ventilation problems now.

Now, what do you people think might be causing this huge mismatch between the BIOS readings and all other applications used to read the temps? Could it be that the mobo is not working fine for some reason? (I reinstalled the old E4400 several times when trying to OC it, so I'm not sure if this could be a problem). Also, what could be causing the temperature to get so high when running stress programs, at stock speed? I think it should be lower in normal conditions.

Greetings and thanks a lot in advance!

(And sorry for the very long post, just wanted to give enough details :D)
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  1. Best answer
    Well, for now All I can do is say try a few basic things:
    -reseat the heatsink again reapplying thermal grease and see if there is a difference
    -If you run everything with the side panel off, is there a difference with the temperatures?

    I have limited experience with the core 2 duo models but the ones at my college run pretty hot. 50 on idle almost 80 on load. The cases are small dells and I can feel the heat coming out the back and see the dust inside. Generally you want your goal to be <60C on load.
  2. I'm also thinking it might be the thermal grease not properly applied (I'm not used to install processors, so I'm not very good with it). Well, I'm going to reset the heatsink as you suggested.
    As for the normal temperatures for this processor, I think they're between 30 º C and 40 ºC on idle, and preferably below 73 º C on load (or at least this is what I understand from what the intel specifications say).

    Well, I will reset the heatsink and post back the results.

  3. Hi, you were right, the thermal grease was not completely spread, and didn't cover the entire heatsink surface, so this might explain why it wen't so high when running stress programs. I reinstalled the heatsink, and applied the thermal grease again, and it's working a bit better now; but still, the temperature may get at around 70 ºC when stressing the processor at full load for more than 5 minutes (may vary depending on the room temperature). Maybe I didn't applied the grease properly (again :( ). I think I will reinstall the heatsink when I have some time (in this way i can also verify if the grease is ok, and if this temperature behaviour is normal or not). Anyway, there's something that still confuses me a bit: everything, on windows on linux shows an idle temperature of 38 ºC, but when I check in the BIOS, the temperature varies, sometimes it stays in 44 ºC for more than 5 minutes, then starts to rise to 49 ºC; it's not a constant temperature, although it generally stabilizes at 45 ºC or 49 ºC. If the real idle temperature as reported by the BIOS is 49 º C, then it would mean that I should add 11 ºC to the temperature readings reported by core temp, real temp, etc.? Is it possible that under some circunstances the temperature on the BIOS may be higher than being in the OS with no load on the processor? Also, this erratic temperature behaviour is shown by an application named OCtuner, which came with the mobo cd's: it may start showing 43 or 47 ºC, then lowers to 38 ºC, although I think when this happens, it reduces the processor speed from 2.93 to around 1.5 automatically (OCtuner is used to overclock, but I'm using it only to read the temperature).

    I think all this has to do with the application of the thermal grease, as I said before, but anyway, any possible explanation for this would be very appreciated :)

    Greeetings, and thanks in advance.
  4. Yeah that's still really hot. I don't feel comfortable unless my CPU is below 60C on load. The bios is normal. I get higher temperatures in my bios too. I think it might have something to do with CPU usage or lack of throttling for power savings in the bios or something.

    When applying the thermal grease you don't want to apply too much. Just enough to fill in the cracks. What's your case cooling like?
  5. Hi,

    As for the throttling settings, I have to check in the bios, but I'm almost sure it's enabled, as well as power saving (I've been checking the bios many times in the last weeks :D).

    As for the cooling, my case doesn't have a good ventiliation system, so, I took off the left side panel. It also has an 8 cm exhaust fan at the rear, near the cpu. The cpu cooler is the stock one (round base, and about 1,5 cm width). I'm about to buy a new case in one week maybe, but in the meantime, I will use the freezer xtreeme cooler to see if there's a difference.

    Thanks again for your help!
  6. Best answer selected by lmorell.
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