Thermal test of iPad's A5X chip shows operating temperature of 97 degrees F

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  • Reply 61 of 106
    jragostajragosta Posts: 10,473member
    Quote:
    Originally Posted by Gatorguy View Post


    Didn't Consumer Reports win that suit? Have they ever been successfully sued for defamation?



    Here's some background:

    http://junksciencearchive.com/consum...r_lat0923.html



    Note that the standards for defamation are pretty high - you must show actual malice and that the information was posted with intent to harm. Because of this, the decision was split. The jury said that CR knowingly published false statements but did not do so with intent to harm, so no damages were awarded:

    http://www.nytimes.com/2000/04/08/bu...r-reports.html



    So, the jury decision was that CR had made a false report.



    Quote:
    Originally Posted by jameskatt2 View Post


    Sure, the iPad has twice the number of LED bulbs. This it is going to be warmer than the iPad 2.



    If that were the explanation, the temperature wouldn't depend on what you're doing with it. As it is, there's a big increase in temperature when you play games or do GPU benchmarks, so the A5X is probably a major contributor.
  • Reply 62 of 106
    tzeshantzeshan Posts: 2,351member
    Quote:
    Originally Posted by AppleInsider View Post


    An external test involved having the two iPads to play movies on Netflix. The third-generation iPad started at 27 degrees C (80.6 degrees F) and warmed up to 32-33 degrees C (89.6-91.4 degrees F), while the iPad 2 started at 24 degrees C (75.2 degrees F) and only climbed to 25-26 degrees C (77-78.8 degrees F).



    [ View article on AppleInsider ]



    Wow! If my kid's forehead is 32-33 degrees C (89.6-91.4 degrees F) I will take him to the emergency room right away. lol
  • Reply 63 of 106
    ivladivlad Posts: 742member
    For once, can people chill out? The chip is running a screen resolution bigger than a 42 inch TV. It's obvious that it will get much warmer.
  • Reply 64 of 106
    kit_ckit_c Posts: 16member
    Quote:
    Originally Posted by VanFruniken View Post


    My point is the following.



    If the iPad 3's external housing gets hotter, it may be partly because of better heat transfer from the processor to the external world. Something already mentioned elsewhere, namely heat produced by other parts such as LED backlights, is not directly contributing to peak temperatures in the processor.



    Further, given that the A5X has a metal housing, it may also be evacuating the heat better than the A4's plastic housing.



    Also, opening up the case may not give a representative idea of the processor temperature, because of different heat conduction to the outer shell.



    The only reliable measurement would be to access the on-chip temperature sensors.

    Maybe there would be no FUD articles to publish if it would actually turn out that the actual dye temperature in the iPad3's processor is hardly different from that in the previous models. Would such a realization put CR, the NYT and others to shame? Probably not, they wouldn't even admit their unscientific mistake. They would simply start looking at something else to pick on.



    ^^^^ This. Lot's of uninformed heat trasfer discussion in this and related threads.
  • Reply 65 of 106
    jragostajragosta Posts: 10,473member
    Quote:
    Originally Posted by tzeshan View Post


    Wow! If my kid's forehead is 32-33 degrees C (89.6-91.4 degrees F) I will take him to the emergency room right away. lol



    That's a good idea. Hypothermia can be dangerous.
  • Reply 66 of 106
    umrk_labumrk_lab Posts: 550member
    "Thermal test of iPad's A5X chip shows operating temperature of 97 degrees F"





    Thank you for the "F" !
  • Reply 67 of 106
    cferrycferry Posts: 26member
    "but he still wants one so he can surf the net he invented."



    I know another member has already posted a Snopes link on this subject, and I apologize that this is off topic, but decent people have to stand up for the truth and against casual slander and politically motivated lies whenever such BS appears. Please note that I'm not attacking the original poster, who I'm sure intended only to be amusing.



    Anyone who still believes that Al Gore ever claimed he invented the Internet should read this. Even Newt Gingrich has defended Gore on this issue, as you'll find if you bother to read this.



    http://en.wikipedia.org/wiki/Al_Gore...ion_technology
  • Reply 68 of 106
    timbittimbit Posts: 331member
    I think these are isolated issues, as each test comes up with different numbers for maximum heat. How can one iPad get up to 116 degrees F but another only get to 100? Makes no sense. Do multiple tests and take the average. More scientific.
  • Reply 69 of 106
    xsamplexxsamplex Posts: 214member
    That's not bad. I run at 98.6 myself.
  • Reply 70 of 106
    afrodriafrodri Posts: 190member
    Quote:
    Originally Posted by Timbit View Post


    I think these are isolated issues, as each test comes up with different numbers for maximum heat. How can one iPad get up to 116 degrees F but another only get to 100? Makes no sense. Do multiple tests and take the average. More scientific.



    Because they are measuring at different points, after stressing the processor in different ways and with the iPad in different positions.



    In all the cases (even the CR test) the qualitative result was the same - its warmer, but not too bad.
  • Reply 71 of 106
    myapplelovemyapplelove Posts: 1,515member
    Quote:
    Originally Posted by jameskatt2 View Post


    This is the silliest topic ever on the iPad!



    Or this is the stupidest topic ever!



    Duh.



    Sure, the iPad has twice the number of LED bulbs. This it is going to be warmer than the iPad 2.



    Big deal.



    Live with it.



    Enjoy it!



    It great during the winter!



    Wow wee!



    Yippee!



    Its faster!



    Stupid.



    I bought mine.



    I love it.



    I love that its warmer!



    The warmth assures me it is faster!



    How fittingly ironic that the post claiming this topic is the silliest ever is the silliest post in this thread.
  • Reply 72 of 106
    I liked the article but have a problem with your methodology and use (or lack of use) of math / science units.



    The issue is that when comparing temperatures and speaking about "hot" and "cold" device temperatures you need to use Kelvin (temps relative to absolute zero) if you want to compare the heat content (AKA Temperature). F temps will exaggerate, C even more so. Kelvin is correct method engineering wise.



    The "hot" device (the iPad (3) ) is 306 K and the "cool" device is 299K.

    This is a 2.28% difference which is probably less than measurement errors.

    (You DID do a minimum of three measurements for each trial didn't you? ;-)



    I don't expect dry engineering writing but a little physics understanding (of basic thermodynamics for example) should be present. Mentioning the basic fact that the new iPad uses 42.5W in 10Hr vs 25W in 10Hr for the iPad2 explains the minor heat increase.



    Consumer Reports need to get engineers to do their testing.

    Their methodology and reporting sucks, is sensationalist and self-serving.



    PeterSW
  • Reply 73 of 106
    jragostajragosta Posts: 10,473member
    Quote:
    Originally Posted by pspicerwensley View Post


    I liked the article but have a problem with your methodology and use (or lack of use) of math / science units.



    The issue is that when comparing temperatures and speaking about "hot" and "cold" device temperatures you need to use Kelvin (temps relative to absolute zero) if you want to compare the heat content (AKA Temperature). F temps will exaggerate, C even more so. Kelvin is correct method engineering wise.



    The "hot" device (the iPad (3) ) is 306 K and the "cool" device is 299K.

    This is a 2.28% difference which is probably less than measurement errors.

    (You DID do a minimum of three measurements for each trial didn't you? ;-)



    I don't expect dry engineering writing but a little physics understanding (of basic thermodynamics for example) should be present. Mentioning the basic fact that the new iPad uses 42.5W in 10Hr vs 25W in 10Hr for the iPad2 explains the minor heat increase.



    Consumer Reports need to get engineers to do their testing.

    Their methodology and reporting sucks, is sensationalist and self-serving.



    PeterSW



    As explained in a different thread, you are incorrect.



    You should be measuring heat gain while in operation. If the iPad 2 is at 70 degrees when turned off and 80 degrees when in use, that's a 10 degree heat gain from operation. If the iPad 3 is at 70 degrees when turned off and 90 degrees when turned on, that's a 20 degree heat gain from operation - or 100% more.



    Of course, neither one is a significant problem and there are no reports of any problems caused by it. Furthermore, there are at least 4 or 5 different reports of external temperatures and none of them come close to Consumer Reports' figures. Most of them put iPad 3 temperatures in heavy use into the 90's, not 116.
  • Reply 74 of 106
    jnjnjnjnjnjn Posts: 588member
    Quote:
    Originally Posted by Hakime View Post


    ... given that the tradeoff in terms of heat to stay at 45 nm for the A5X chip is quite small, few percent. The fact that you feel that the new iPad is warmer is because there are several reasons adding up, bigger battery, more pixels, etc.. But again the final difference in heat production is quite small. ...



    In fact most of the heat comes from the processor chip (thats why the heat is localized) and that is confirmed by tests that measure the temperature of the chip itself.

    Reducing the feature size to 32nm from 45nm will reduce the dissipation (heat production) with a factor of almost 3, if the chip design is unaltered and the clock frequencies stay the same.

    So that's a very big difference.



    J.
  • Reply 75 of 106
    jnjnjnjnjnjn Posts: 588member
    Quote:
    Originally Posted by jragosta View Post


    As explained in a different thread, you are incorrect.



    You should be measuring heat gain while in operation. If the iPad 2 is at 70 degrees when turned off and 80 degrees when in use, that's a 10 degree heat gain from operation. If the iPad 3 is at 70 degrees when turned off and 90 degrees when turned on, that's a 20 degree heat gain from operation - or 100% more.



    Of course, neither one is a significant problem and there are no reports of any problems caused by it. Furthermore, there are at least 4 or 5 different reports of external temperatures and none of them come close to Consumer Reports' figures. Most of them put iPad 3 temperatures in heavy use into the 90's, not 116.



    Exactly, it's the temperature delta that counts. And in that case the scale (celsius, kelvin, fahrenheit) doesn't matter.



    J.
  • Reply 76 of 106
    jragostajragosta Posts: 10,473member
    Quote:
    Originally Posted by jnjnjn View Post


    In fact most of the heat comes from the processor chip (thats why the heat is localized) and that is confirmed by tests that measure the temperature of the chip itself.

    Reducing the feature size to 32nm from 45nm will reduce the dissipation (heat production) with a factor of almost 3, if the chip design is unaltered and the clock frequencies stay the same.

    So that's a very big difference.



    J.



    First, I don't believe your numbers.



    More importantly, reducing it to 11 nm would also reduce the heat generation - but 11 nm isn't ready either. What's the point of talking about something that isn't available.



    Oh, and btw, some reports suggest that a lot of the heat is coming from the CPU, but a good bit also comes from the battery. If you discharge a battery quickly, it heats up.
  • Reply 77 of 106
    Quote:
    Originally Posted by umrk_lab View Post


    You use whatever unit you like. But please, considering the worldwide audience you have, change such titles into "Thermal test of iPad's A5X chip shows operating temperature of 97 degrees F" (that would prevent me from having a heart attack)



    Really they should't have the "A5X chip" in the title -- when it's quickly concluded that the added heat is mostly due to the higher resolution screen.



    About 8 degrees higher? I think it's probably a small miracle it wasn't even hotter than that.
  • Reply 78 of 106
    I would think a good solution would be for Apple to due a software update, creating a "Normal" and "Turbo" mode in settings. The "Turbo" mode mainly for hard gaming or hd viewing, and "Normal" mode for pictures, browsing, reading, etc.
  • Reply 79 of 106
    jragostajragosta Posts: 10,473member
    Quote:
    Originally Posted by Fake_William_Shatner View Post


    Really they should't have the "A5X chip" in the title -- when it's quickly concluded that the added heat is mostly due to the higher resolution screen.



    I don't think so. Look at the table at the beginning of this thread.



    At idle, iPad 3 is 1 degree warmer than iPad 1 or 2.



    Web browsing, iPad 3 is 3 degrees warmer than iPad 1 or 2.



    Watching a YouTube video, iPad 3 is 4 degrees warmer than iPad 1 or 2.



    Playing Infiniti Blade, iPad 3 is 4-9 degrees warmer than iPad 1 or 2.



    The amount of heat generated by the screen is likely the same in all of those cases (the screen's heat is mostly from the backlight). The harder you stress the CPU and GPU, the more the iPad 3 gains on the earlier versions. That suggests pretty strongly that it's mostly the CPU/GPU which accounts for the difference. Also, note that on Infinity Blade, the iPad 2 is considerably warmer than iPad 1. The screens are the same, but the CPU/GPUs are different - once again confirming that it's the CPU/GPU that accounts for the difference.



    Now, it is true that the higher resolution screen is the reason for the faster GPU, but it's the GPU generating the heat, not the screen.
  • Reply 80 of 106
    solipsismxsolipsismx Posts: 19,566member
    Quote:
    Originally Posted by jragosta View Post


    I don't think so. Look at the table at the beginning of this thread.



    At idle, iPad 3 is 1 degree warmer than iPad 1 or 2.



    Web browsing, iPad 3 is 3 degrees warmer than iPad 1 or 2.



    Watching a YouTube video, iPad 3 is 4 degrees warmer than iPad 1 or 2.



    Playing Infiniti Blade, iPad 3 is 4-9 degrees warmer than iPad 1 or 2.



    The amount of heat generated by the screen is likely the same in all of those cases (the screen's heat is mostly from the backlight). The harder you stress the CPU and GPU, the more the iPad 3 gains on the earlier versions. That suggests pretty strongly that it's mostly the CPU/GPU which accounts for the difference. Also, note that on Infinity Blade, the iPad 2 is considerably warmer than iPad 1. The screens are the same, but the CPU/GPUs are different - once again confirming that it's the CPU/GPU that accounts for the difference.



    Now, it is true that the higher resolution screen is the reason for the faster GPU, but it's the GPU generating the heat, not the screen.



    I think Soneria came up with that idea but his hypothesis ever once addressed why he doesnt think it's the GPU, the size of the chip, the RAM no longer a PoP, or why there is now a heat sink when before there was none. I'm not sure if he's being dishonest or if jut has blinders for displays but it's shortsighted no matter how you look at it.



    One can test this, too, by playing IB2 at full brightness and lowest brightness to see to what degree the heat differs.
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