Weird temperature readings

[snakeye]

I just left my computer idling for around 30 minutes, and the graph in speedfan shows that the core temp stayed at room temperature. Normal, right? The weird thing is I left my computer idling yesterday as well, and it peported temperatures as low as 17 celcius. Same results with coretemp. Any ideas as to what may be going on? I'm not sure if they're reporting the correct temperature anymore.

Using an x3 720 on a gigabyte mobo.

 

[mentalcrisis00]

In my opinion on air cooling the cpu temp can't be lower than the room temp, generally the case ambient temp is higher than the room. In my case it's 20C in my room and about 25 to 27C in my case with a cpu temp of about 27 to 34. I think the only way it could report lower is if you had a liquid cooler or phase change cooling. Liquid coolers do get lower temps if the computer is in idle, but for a fan cooler it would have to be blowing cold air into the heatsink. If the air in the room is a certain temp the cpu temp should reflect that if you have room air coming in and hot air from the case going out.

Thats at least how I see it from my point of view, someone please correct me if I'm wrong. Perhaps if the cpu were powered down it could be cooler but you wouldn't be able to see temps in speedfan if it were lol. More than likly you have a stuck thermal sensor in the cpu or speedfan is reporting the wrong results. Sometimes speedfan will report lower temps then their actually are. Try a program called HWMonitor or the beta version of speedfan as it has updates for more current chipsets. I've heard of people having stuck sensors on the intel cpu's where it will report 1 temp constantly regardless of load. The good thing about HW monitor is that it generally shows cpu Die temp and core temps, at least on my intel it does because it has sensors for each one.

HW monitor

Speedfan 4.38 Beta 14 at softpedia

 

[BonzaiDuck]

Originally posted by: snakeye
I just left my computer idling for around 30 minutes, and the graph in speedfan shows that the core temp stayed at room temperature. Normal, right? The weird thing is I left my computer idling yesterday as well, and it peported temperatures as low as 17 celcius. Same results with coretemp. Any ideas as to what may be going on? I'm not sure if they're reporting the correct temperature anymore.

Using an x3 720 on a gigabyte mobo.

I'm not familiar with that processor, and tentatively assume it is an AMD CPU.

I can tell you matter-of-factly that the following sorts of peculiarities emerged as Intel released their Penryn (Wolfdale and Yorkfield) cores. Motherboard makers who had released mobos for the earlier Conroe processors did not keep up with a change in how temperature sensors are read under the Penryn models.

It took several months before BIOS revisions showed temperature readings more in line with what one would expect with the new cores.

Further, again in the Intel context, Wolfdale and Yorkfield processors were known to be defective or "stuck" for the core sensors. They wouldn't register accurate temperatures until the core temperatures had exceeded the "stuck" values. Intel also issued a disclaimer statement that "the sensors were not meant to measure idle temperature values" -- or measure them accurately.

For the volume of thoughts I'm posting here, it probably exceeds what I should offer to an AMD user ( . . . that IS the type of processor you're using, isn't it?)

Also, mentalcrisis00 is absolutely correct about choice of thermal monitoring software. Those that seem to give the best results are:

HWMonitor
Everest Ultimate [appropriate revisions]
Coretemp
RealTemp

SpeedFan has been notorious for misleading or inaccurate readings -- at least for several of the newer CPUs. I don't see how SpeedFan's author -- Alfredo Comparetti -- would be any more diligent updating the software for AMD cores than for those by Intel.

 

[snakeye]

Thanks for the replies. I did try all of the softwares that you mentioned in your post BonzaiDuck, and they all report the exact same core temp, which I believe is also the same as the one in the bios. Stuck sensor is a possibility, however I searched the net and didn't come up with much info about anyone else having the same problem as me.

 

[soccerballtux]

Originally posted by: BonzaiDuck

Originally posted by: snakeye
I just left my computer idling for around 30 minutes, and the graph in speedfan shows that the core temp stayed at room temperature. Normal, right? The weird thing is I left my computer idling yesterday as well, and it peported temperatures as low as 17 celcius. Same results with coretemp. Any ideas as to what may be going on? I'm not sure if they're reporting the correct temperature anymore.

Using an x3 720 on a gigabyte mobo.

I'm not familiar with that processor, and tentatively assume it is an AMD CPU.

I can tell you matter-of-factly that the following sorts of peculiarities emerged as Intel released their Penryn (Wolfdale and Yorkfield) cores. Motherboard makers who had released mobos for the earlier Conroe processors did not keep up with a change in how temperature sensors are read under the Penryn models.

It took several months before BIOS revisions showed temperature readings more in line with what one would expect with the new cores.

Further, again in the Intel context, Wolfdale and Yorkfield processors were known to be defective or "stuck" for the core sensors. They wouldn't register accurate temperatures until the core temperatures had exceeded the "stuck" values. Intel also issued a disclaimer statement that "the sensors were not meant to measure idle temperature values" -- or measure them accurately.

For the volume of thoughts I'm posting here, it probably exceeds what I should offer to an AMD user ( . . . that IS the type of processor you're using, isn't it?)

Also, mentalcrisis00 is absolutely correct about choice of thermal monitoring software. Those that seem to give the best results are:

HWMonitor
Everest Ultimate [appropriate revisions]
Coretemp
RealTemp

SpeedFan has been notorious for misleading or inaccurate readings -- at least for several of the newer CPUs. I don't see how SpeedFan's author -- Alfredo Comparetti -- would be any more diligent updating the software for AMD cores than for those by Intel.

Speedfan was right all the while that RealTemp and CoreTemp were wrong back when there was all that confusion over Intel-- they were reporting my CPU as 89C (Speedfan was 74...15c difference). I think Speedfan is fine.

 

[snakeye]

http://img2.imageshack.us/my.php?image=speedfancold.gif

Weird, seems like it's jumping up to room temperature and then going back down to the lowest, which is 16-17 degrees (while idling).

 

[mentalcrisis00]

I imagine the sensor is stuck or your bios/board are not reading the temp properly. Usually the motherboard detects the temps from the cpu, and the software just reads what the motherboard tells it. So if not a stuck sensor it could be a faulty reading from the board, or it could just be that you need a bios update. Go to your motherboards support page on the manufacturers website and see if there is a new bios. Keep in mind a bios flash could result in damaging your board if it is interrupted. I suggest using the download bios to desktop method and use whatever utility the manufacturer gives you to update it offline, some places have over the internet updaters which i don't like cause connections can get interrupted. If you've already done this than I guess it'll just be one of those quirks you have to live with. Does speedfan show you a core temp? usually people follow the core temp more than cpu temp because it's a little more accurate. As I said before if it's an AMD it might only have 1 sensor.

 

[Elganja]

speedfan always reads ~15C less then everest, coretemp and realtemp. I stopped using it a longtime ago and just stick to everest (mainly because of the nifty vista sidebar gadget).

so you may want to try a different program...

 

[mentalcrisis00]

huh i never knew that, I stopped using it cause I got sick of setting it up cause it does exactly tell you what every reading is and you usually have to guess. HW monitor and everest just tell me straight out when every reading is.

 

[snakeye]

I don't know why you guys get different results with different programs. I've tried everest, speedfan, coretemp, crystalCPUID, and they all reported the exact same temperature, for all the sensors (core, gpu, hdd, system)

I did update the bios, but it didn't help. I guess I'll check with gigabyte support, just thought I'd ask here cause I thought it would have been a more common issue.

 

[Zap]

Originally posted by: snakeye
temperatures as low as 17 celcius. Same results with coretemp. Any ideas as to what may be going on? I'm not sure if they're reporting the correct temperature anymore.

Of course it is reporting the right temperature. [/shiftyeyes]

After all we enthusiasts have come to expect below ambient idle temperatures on air cooling and unrealistically low temperatures under load.

 

[snakeye]

Originally posted by: Zap

Originally posted by: snakeye
temperatures as low as 17 celcius. Same results with coretemp. Any ideas as to what may be going on? I'm not sure if they're reporting the correct temperature anymore.

Of course it is reporting the right temperature. [/shiftyeyes]

After all we enthusiasts have come to expect below ambient idle temperatures on air cooling and unrealistically low temperatures under load.

Just cause a temperature of 17 degrees is reported doesn't mean the higher temperatures aren't accurate, when the CPU is being used.