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TrimmTrabb

macrumors member
Original poster
Apr 10, 2012
46
0
I thought this might be helpful to anyone who's concerned about heat with their new iPad. This isn't to rehash the long discussions about whether the iPad gets too hot or not. This is simply to help anybody who doesn't have measuring equipment and wants a better understanding of how hot their iPad gets.

No jailbreaking or anything funky required!

Step 1: Under Settings > General > About > Diagnostics & Usage, ensure this is set to Automatically Send.

Step 2: On this same screen, go to Diagnostic & Usage Data. In that list, you should find a log called log-aggregated-YYYY-MM-DD.plist where the date of that file should be 2 days ago.

Note that if you had the setting in Step 1 originally set to Don't Send, it may take until midnight for your iPad to create the log file. Look for it the next day.

The iPad automatically creates this log file every night and sends it to Apple. It always appears to be for 2 days ago. So you'll have to wait a couple of days to see the readings for any heat you experience on your iPad today.

Step 3: Inside the log file, you'll see temperature readings for the internal sensors of your iPad. Although you may see a few entries, I believe those are just multiple readings, but only one sensor is used on the WiFi model, and two sensors (one on the baseband) on the 4G model.

The entry should look something like this:

<key>com.apple.cltm.Temperature1</key>
<array>
<real>18.52</real>
<real>33.009999999</real>
<real>23.4532211</real>
…..


My educated guess is that for each entry like this, the 1st value is the lowest temperature recorded, the 2nd is the highest temperature recorded, and the 3rd is the average or median temperature. All measurements are in Celsius.

Feel free to post your own readings here. In particular, if you feel your iPad is genuinely suffering from excessive heat issues, then giving the community here your temperature readings may help us give advice, or show that your iPad is normal and the perception of high heat is just subjective.
 
Last edited:

squidkitten

macrumors 6502
Mar 10, 2012
327
35
Omaha
If your educated guess on the meaning of the readings is correct, then the hottest my iPad has gotten (as seen between all of the logs) is about 36.07ºC, so just below average human body temperature, though it typically runs much lower.

I've never been particularly bothered by any heat from my iPad. Occasionally it does feel noticeably warmer when I have it running a strenuous app for a while, but nothing uncomfortable. Definitely no where near as hot as my MBP gets.

On average, it's running at a nice, comfortable 73º F.
 

Menel

Suspended
Aug 4, 2011
6,351
1,356
Uh oh,
Code:
<key>com.apple.cltm.Temperature1</key>
		<array>
			<real>20.559999999999999</real>
			<real>34.509999999999998</real>
			<real>27.543395680249336</real>
			<real>53566.34151587636</real>
			<integer>4491</integer>
		</array>
Thats like 96,000 F!
 

TrimmTrabb

macrumors member
Original poster
Apr 10, 2012
46
0
Uh oh,
Code:
<key>com.apple.cltm.Temperature1</key>
		<array>
			<real>20.559999999999999</real>
			<real>34.509999999999998</real>
			<real>27.543395680249336</real>
			<real>53566.34151587636</real>
			<integer>4491</integer>
		</array>
Thats like 96,000 F!

Ha. I have no idea what the 4th and 5th values are. So ignore those. Only the first three values are clearly temperature readings.
 

TrimmTrabb

macrumors member
Original poster
Apr 10, 2012
46
0
Nice find Trimm.

+1

Thanks.

I'm especially interested if anybody gets to temperatures over 45C, which is the upper limit that Apple recommends for storing the devices. However, as the temperature sensor might be on the CPU itself, it wouldn't mean that the iPad itself is "overheating". It would be interesting to hear from people who have pushed their iPads hard at 100% brightness.

This relates to another thread I started about temperature limits for lithium polymer batteries, and whether excess iPad heat could be a concern. Unlike a laptop, the iPad battery is housed snugly against the casing, logic board, and display LEDs, and would be soaking up that heat to a greater extent.
https://forums.macrumors.com/showthread.php?p=14699763#post14699763
 

iHeartsteve

macrumors 68000
Feb 12, 2012
1,572
924
Cool! I had an apple genius do this to one of their hand held devices but I didn't know you could do it yourself right on the iPad!
 

ZipZap

macrumors 603
Dec 14, 2007
6,112
1,467
Uh oh,
Code:
<key>com.apple.cltm.Temperature1</key>
		<array>
			<real>20.559999999999999</real>
			<real>34.509999999999998</real>
			<real>27.543395680249336</real>
			<real>53566.34151587636</real>
			<integer>4491</integer>
		</array>
Thats like 96,000 F!

Where the hell are all the "It does not get hot" blow-hards when you need them.

That's pretty hot. Can you still hold the iPad? Cause if you can, then you dont have a heat issue. :rolleyes:
 

TroyBoy30

macrumors 68030
Jun 9, 2009
2,573
1,404
Atlanta GA
so youre saying you think it really got to 96,000 degrees f? :confused:


pretty sure what people have said is...'mine doesn't get hot', not 'none of the them get hot'
 

Batavian

macrumors 6502
Mar 10, 2011
464
38
I'm wondering if using a back cover makes a difference in heat. Were any of these results using a back cover? The aluminum back is a very effective heat sink and I'm wondering if bottling that heat is not good.
 

brentsg

macrumors 68040
Oct 15, 2008
3,579
936
Where the hell are all the "It does not get hot" blow-hards when you need them.

That's pretty hot. Can you still hold the iPad? Cause if you can, then you dont have a heat issue. :rolleyes:

That is not hot.

32.5C is a pretty typical temperature for the fingers, so we're talking about the temperature measured by a diode that is likely embedded inside a chip, that is embedded inside a device being a MAX of 2C higher for this user.
 

Menel

Suspended
Aug 4, 2011
6,351
1,356
Where the hell are all the "It does not get hot" blow-hards when you need them.

That's pretty hot. Can you still hold the iPad? Cause if you can, then you dont have a heat issue. :rolleyes:
Pretty hot, my comment about 96,000F is a joke.

The high temp there is 34.5C, which is below normal body temperature, and very low for an IC.

nVidia/Intel chips can safely operate as high as 100C depending on model.

----------

I'm wondering if using a back cover makes a difference in heat. Were any of these results using a back cover? The aluminum back is a very effective heat sink and I'm wondering if bottling that heat is not good.
See my post above, mine has a ZAGG LEATHERskin on the rear.
 

TrimmTrabb

macrumors member
Original poster
Apr 10, 2012
46
0
Looks like someone on the Apple Discussion boards got up to over 46C in his log file.
https://discussions.apple.com/thread/3810951?start=390&tstart=0
https://discussions.apple.com/servlet/JiveServlet/showImage/2-17915468-100054/photo.PNG

To me, that sounds like it would become a concern in certain situations. I don't have a degree in thermodynamics so feel free to correct me, but if the iPad has a case or something on the back to trap that heat, and other components like the battery start to reach over 45C, that's when gradual damage can start to occur. My guess is that user is pushing the thing to its limits as in another thread he complains that the iPad doesn't charge when plugged in and being used.
 

brentsg

macrumors 68040
Oct 15, 2008
3,579
936
Yeah, not an issue.

One user reached what would be an uncomfortable temperature to touch, were the chip being measured accessible.

It sounds like that individual was engaging in usage that should push temps up. Heck, I'm used to my MBP pushing 90C+.
 

Fruit Cake

macrumors 6502a
Mar 31, 2012
597
20
My battery gets to about 34,5celcius unde autumn weather, the iPad can get hot, but it would shutdown before it reaches critical temps. Will be interesting to see how they fare up in the north American summer in a few months time...
 

eq2675

macrumors regular
Apr 16, 2008
122
0
I'm wondering if using a back cover makes a difference in heat. Were any of these results using a back cover? The aluminum back is a very effective heat sink and I'm wondering if bottling that heat is not good.

I'm using the Incase Book Jacket and getting average temperatures of 25c

31Jqq9NrhoL._SS400_.jpg
 

PrayForDeath

macrumors 6502
Jan 3, 2012
304
83
<key>com.apple.cltm.Temperature5</key>
<array>
<real>26.57</real>
<real>45.149999999999999</real>
<real>33.526672036985232</real>
<real>232011.81018847038</real>
<integer>14276</integer>
</array>


Should I be worried? lol
 

TrimmTrabb

macrumors member
Original poster
Apr 10, 2012
46
0
<key>com.apple.cltm.Temperature5</key>
<array>
<real>26.57</real>
<real>45.149999999999999</real>
<real>33.526672036985232</real>
<real>232011.81018847038</real>
<integer>14276</integer>
</array>


Should I be worried? lol

Well nobody knows for sure what the values represent, and as I said at the top, those are just my best guesses as to what the first 3 values mean.

But let's assume they mean what I think they do: does it seem right to you that the low for that day was 26.5C (80F)? That feels a bit warm! Unless you live somewhere hot with no aircon...

My low temperatures are between 15C and 18C, which is dead accurate in terms of the room temperature in my house. I figured that reading is from when the iPad was sleeping and not plugged in. I suppose that if your iPad is always on the charger while you're not using it, that could bump up the internal temperature higher than room temperature, even when it's in sleep mode.
 

iapplelove

Suspended
Nov 22, 2011
5,324
7,638
East Coast USA
Here is mine..

No idea what it means but mine hardly gets warmer than my ipad2

key>com.apple.cltm.Temperature1</key>
<array>
<real>20.73</real>
<real>36.020000000000003</real>
<real>25.726655011654955</real>
<real>46507.200299650125</real>
<integer>2574</integer>
</array>
 

sekazi

macrumors 6502
Jan 12, 2012
469
84
Mine shows 161,139 F

<key>com.apple.cltm.Temperature1</key>
<array>
<real>18.59</real>
<real>35.450000000000003</real>
<real>26.439323765786426</real>
<real>89504.631916979008</real>
<integer>8710</integer>
</array>
<key>com.apple.cltm.Temperature3</key>
<array>
<real>17.850000000000001</real>
<real>34.530000000000001</real>
<real>25.081995407577384</real>
<real>79450.194919815272</real>
<integer>8710</integer>
</array>
<key>com.apple.cltm.Temperature5</key>
<array>
<real>19.5</real>
<real>35.399999999999999</real>
<real>27.06195063145805</real>
<real>77056.149958772541</real>
<integer>8710</integer>
 
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