Update on Froyo CPU Temps

bigchris

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Excelent! I didnt have a pull down but there was a check box at the top of the options to use the CPU temp. I did that it is now accurate. It is amazing how much it jumps though. it was sitting at 78, i then browsed the net for a couple minutes, it jumped to 104.8 then shut down the browser and it drop back to 82 instantly. So that was a 22.8 degree drop in 10 seconds (that is the update interval I have it set at).

-Chris Brock
 

LT*

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Oops, you're right, check box. Glad it's up and running for you.
 

bigchris

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I am still just not comfortable that the temp readings are accurate. I have been in a meeting for the last hour and my phone was in standby on my desk. When I unlocked it the temp readings according to the SetCPU widget were as follows:

58f (12 degrees below room temp?:dry:)
68f
81f
90f
75f

These were taken in 10 second intervals. I just cant believe that the temp would rise 32 degrees and then fall 15 in a 40 second time period. Maybe the CPU sensor is just that close to the heart of the CPU that the slightest change is processor load makes that big of a difference? Even if that is true I still have never heard of a CPU actually running colder then the ambient room temp without some type of cooling system. Any thoughts or anyone else experiencing these behaviors?

-Chris Brock
 
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Dustinmj

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I am still just not comfortable that the temp readings are accurate. I have been in a meeting for the last hour and my phone was in standby on my desk. When I unlocked it the temp readings according to the SetCPU widget were as follows:

58f (12 degrees below room temp?:dry:)
68f
81f
90f
75f

These were taken in 10 second intervals. I just cant believe that the temp would rise 32 degrees and then fall 15 in a 40 second time period. Maybe the CPU sensor is just that close to the heart of the CPU that the slightest change is processor load makes that big of a difference? Even if that is true I still have never heard of a CPU actually running colder then the ambient room temp without some type of cooling system. Any thoughts or anyone else experiencing these behaviors?

-Chris Brock

This is pretty interesting... by chance was your desk cooler than ambient room temperature? I know mine usually is cool to the touch when the room gets warm. If so, that may be your explanation right there, as the metal plate on the back of your phone (next to the camera) is actually a heat spreader tied directly to the cpu.

The cpu sensor itself is integrated into the omap chip, that is, it's VERY close to the core.

The cpu temp driver interfaces directly with the TI chip, taking readings at the proper times as outlined in the omap35xx technical manual.

Log story short... this is the best reading we can get from this hardware. Hope this helps alleviate some of your concern :)
 

serveitup911

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I often had cpu temps reported below ambient on 2.1 kernels that had mature temp monitoring. The temp monitoring can only be as accurate as the information that the sensor gives it. I'm pretty sure it's not possible to have a passively cooled processor below room temp, so let's hope the sensor is precise, if not accurate.

The reason the desk feels cold is it transfers the heat from your skin more effectively than the air. This is the same reason 70 degree water feels cold to swim in, but 70 degree air is comfortable. The water is much better at transferring heat.
 

bigchris

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Very "cool" info (sorry for th terrible pun) and it definitely does make sense. If the metal backing is helping to disperse heat and it was on a solid surface to transfer it into then I could see if actually being cooler then room temp. And knowing now that the sensor is that close to the core I can definitely see how it could change very quickly.

I do know that the highest temp I have seen mine spike to is 112.7 running at 1.2ghz and standard voltage (P3's 1.2ghz sv kernel). And that was after some fairly heavy usage. So given these facts I have to say I am much more comfortable at this point.

Thanks for the help!

-Chris Brock
 

MrRChitty

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P3Droid Kernel is not reporting temp from CPU. Moto Droid rooted stock FRG22D with LV125-1000 32-kernel. Using SetCPU and tempmonitor paid version. LV250-1000 doesn't show either.

Any takers....
 
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