CPU vs. Core Temps - anyone seen this one?

hartmri

Distinguished
Mar 6, 2009
3
0
18,510
I know this thread is out there a million times since I've done some research, but I've yet to find my particular situation. I apologize since I'm at work and don't have any screenshots, but I'll give you the details as best I can.

Just did a build with a Q6600 (G0), running at stock speeds and voltages on an Asus P5Q with a Zalman 9500 cooler. System has been rock solid for almost a week, from the time I built it. I am thinking of overclocking a bit, but wanted to let it settle in for a while first and make sure the temps were consistent.

I have noticed a strange occurence - I use Everest, SpeedFan, and RealTemp (latest versions just downloaded) and I notice my core temps range from 20-30C, perhaps peaking 35-40 under load. That's all good. Normally, the CPU temp is in the same ballpark, within +/- 5-10C, so I wasn't worried about it, and read that the core temps are the ones to watch. Then, I've noticed several times the core temps haven't changed (still 25-30C), and the CPU temp is reading 109C!!! Always 109C too, when it gets that high. Other temps (GPU, HDD are within parameters, it's just the CPU temp off the chart. Systems runs just fine, no thermal shutdown or anything.

Is it possibly the sensor is bad inside the CPU? I was worried that the cooler maybe wasn't placed right, but my core temps are all within 1-2C of each other, all the time.

Any thoughts? When I get home later I can post some screenshots. On boot the CPU temp is fine, just seems to take a while to get that high.
 

mamw93

Distinguished
Jan 16, 2009
540
0
18,980
Ok man here is what I did for that exact problem. I also have an ASUS motherboard (P5Q-E) and I whipped out my driver disc and get both the AI Suite and PC Probe II which is a little better than Real Temp and Everest. I have my case loaded down with 6 120mm fans and the CPU fan at 100% but Real Temp and Core Temp were saying that my computer idled at 92 Fahrenheit. I knew that was wrong so when I got out the PC Probe II it said that I idle around 70 Fahrenheit which seems more feasible because it also said my case temp was about 80 Fahrenheit and when I put my hand inside it indeed felt 80. I have had many people tell me that Core Temp and Everest were giving false readings. PC Probe II must use a different way to read it because even though Real Temp gives you the temp of the hottest core, my lowest core temp was about 5 degrees off of what PC Probe II said was my hottest. I hope this helps man.
 

Mondoman

Splendid
mam, that's a totally different "problem" than the OP's!
OP - could be a glitch in the BIOS, in the MB circuitry, or in the temp sensor in the CPU. I wouldn't worry about it. Remember that the core temps are self contained (converted into a temp number inside the CPU), while the "CPU" temp has a sensor in the CPU that connects to a chip on the MB and uses lookup tables in the BIOS.
 

major53

Distinguished
Sep 19, 2007
502
0
18,980
hartmri mondoman is probably right Ive got a E8400 core 2 duo and when I read the different core.(core 0 = 17c and core 1 =37c)speddfan and real temp etc all say the same. bios read cpu @ 29c start up and hardly get past 38 with load. conctacted intel via e-mail and that could be either diode sensor or the other senor on cpu could be bad.I have not had any problem with this pc and when I run it for several hours I"ll take side case off and just put my fingers on the cpu heatsink just to fill if it is getting hot.aways cool to the touch. if it's running stable it should be ok.
 

Zorg

Splendid
May 31, 2004
6,732
0
25,790
hartmri, Mondoman is right something is glitched. What are you reading the CPU temp with?

mamw93, I don't agree that the AI Suite and PC Probe II are better than Real Temp or Everest. AI Suite and PC Probe are probably reading Tcase from the BIOS not Tjunction.

major53, you have a E8400 not a Q6600. The 45nm CPUs have a known bug with idle temps. Usually they are high, but in any case generally wonky.

Read the Core 2 Quad and Duo Temperature Guide for detailed information on how to properly calibrate your sensors and load test your temps.

 

hartmri

Distinguished
Mar 6, 2009
3
0
18,510
All, thanks for the replies. I have been using them all - RealTemp, CoreTemp (both of which I know don't give me CPU Temp), Everest, PC Probe 2 and SpeedFan. The core temps and CPU temps have been consistent with all the tools, it's just been the CPU temp that seems to rise over time to top out at 109C - in all the tools. I tend to leave the PC on all the time, but when I reboot it's right around 20-25C and by the time I get home from work it's reading 109C, but the cores are stable around 25-30C.

I did some other looking through googling "Q6600 + 109C" and it seems that this isn't an isolated problem - didn't think to enter the temp in the searches I did before. The consensus seems to be some sort of a glitch in the MB/BIOS or the CPU itself.

I guess the next question is this - do I not worry about it as long as the core temps are fine, or do I need to look at replacing the CPU and/or MB? I don't want to get into this endless cycle of swapping parts in and out if this is nothing I need to be concerned about. So far - it's not been too much of a concern, but I wanted some feedback before I started to overclock.

 

tsd16

Distinguished
Jan 11, 2008
333
0
18,790
I am starting to think Asus boards are whacked in some cases when reading the CPU temp as opposed to core temps. From what I gather the CPU temp should always be lower than core temps. But my Asus P6T is reading the CPU temp 10c higher than the hottest core at idel. Ive used about 4 temp monitoring programs, Real temp and core temp read the same values for my cores (29-35c idle) Everest reads my cores at 29-35c and CPU temp at 44c idle, speedfan and Asus Probe (and bios health monitor) read cpu temp at 44c. So all of these different methods of temperature reading are not differing from eachother, so they are consistant, but I believe my CPU temp is being read inaccurately by my motherboard(since according to everything ive been told and read so far the CPU temp should be lower than the core temps), and after searching the net most threads etc. I find where the CPU temp isn't jiving with what it should be according to the core temps, its always been an asus board.

Also, is your cput throttling under load (i.e. slowing down?) at 109c idle I would assume you hit that things threshold under load and it would start throttling, if it isn't then you know damn well the mb is reporting that cpu temp inaccurately.