Expert: iPad heat claims overblown, not a real issue

“DisplayMate Technologies Corporation president Ray Soneira has delved further into the technology behind the new iPad’s Retina Display as well as its relationship to the battery and come up with a simple conclusion: the new iPad, operating normally, should run a bit warmer than the previous model,” Electronista reports.

“He calls the thermographic portraits circulating the web ‘overblown’ and says the extra heat is the natural consequence of increased power,” Electronista reports. “The third-generation iPad uses 2.5 times as much backlight power to illuminate the new display at the same luminance levels as the previous model, Soneira found. The high pixels-per-inch (PPI) ratio of the new display makes the LCD have a lower light efficiency and thus power efficiency. The doubled number of LEDs also give off 2.5 times as much heat, but remarkably the new battery in the iPad manages to (mostly) compensate for the increase.”

“The number of backlight LEDs has risen from 36 to an estimated 72 to 82, contributing heavily to the need for a battery with 70 percent more output than the previous model,” Electronista reports. “Soneira calls for future iPads to employ IGZO displays as soon as possible, saying the display technology pushed by Sharp offers even more efficiency and lower cost than the LTPS technology used in the iPhone. After a production delay, Sharp is expected to start supplying displays for iPads along with Samsung and LG Display, though it is not expected to incorporate IGZO technology at this point.”

Read more in the full article here.

Related articles:
Consumer Reports’ bombshell: New iPad runs hotter than predecessor but ‘not especially uncomfortable’ – March 20, 2012
FUD Alert: Consumer Reports to ‘investigate’ reports of iPad and ‘excess heat’ – March 20, 2012
Like clockwork: Let the iPad ‘overheating’ FUD begin! – March 20, 2012
Infrared test shows more powerful new iPad running a safe 10-degrees warmer than iPad 2 – March 20, 2012


  1. Just wait until Apple invents or perfects the technology that will take that excess heat and convert it back to re-charge the battery to prolong battery life…. I’ll bet they are working on the concept already.

        1. The quality of the thermal energy is the key to efficient energy conversion. You need significant delta T to generate useful electrical energy for something like an iPad, and the temperature difference between the iPad case and the ambient environment is not worth the effort to implement a recovery system. You don’t want the iPad to get hot enough to generate steam, and thermoelectric conversion is a useful, but low efficiency approach. Besides, any energy recovery system would add significant mass, and that would be anathema for a portable electronic device.

          The best strategy by far is for Apple to continue working internally and with its suppliers to continue improving iPad technologies to reduce energy consumption by the display, CPU/GPU, and RF chips. Greater efficiency in these areas means extended battery life and reduced waste heat. The best way to save energy is to avoid wasting it in the first place. Recovering/recycling energy is a distant second in most cases.

  2. “The doubled number of LEDs also give off 2.5 times as much heat.”

    Ummm.. no. The production of photons within an LED does not generate heat (they are NOT tiny light bulbs!). The additional power required to light those extra LEDs does generate heat in the rest of the circuitry. Major heat sources would be the CPU, GPU (bigger in the new iPad) and the battery.

    Regardless, every one needs to lighten up on something that doesn’t even rise to the level of “mildly uncomfortable”, much less “hot”. It’s like determining the purchase of a car based on the engine’s RPM, and ignoring the added luxuries, increased performance and maintaining the same MPG.

    1. Ummm… Yes. I’m not sure where you get the idea that LEDs don’t dissipate any heat; that idea is patently false. LEDs are semiconductors, and like all semiconductors, dissipate heat. In fact, most LEDs dissipate more power in the form of heat than they do light!

      I have no idea how much heat the new backlight contributes in comparison to the other heat-generating components, but the backlight is indeed putting out more heat.

      The bottom line is I see no reason to doubt the President of DisplayMate based on the power consumption figures. Unless LED efficiency changed significantly (it didn’t), then there would indeed be 2.5 times the heat dissipation.

      You are correct though that the sensationalism needs to stop.

      1. I think you are both right. LEDs give off a little bit of heat nd having twice as many more LEDs would give off some additional form of heat. I agree with Aryu and say that the CPU is the more likely culprit.

        But we are just splitting hairs in this heatgate issue.

      2. Hopefully, Apple’s suppliers implemented more efficient LEDs for the backlight. The efficiency of high power LEDs for home and business illumination have doubled in recent years, from 60 lumens/watt to 120+ lumens per watt. But the new display apparently has a lower transmission efficiency, meaning that you need more backlight to achieve the same apparent brightness.

        All of this just renews my appreciation for the design and engineering of the new iPad. No one but Apple could have brought this display technology and the supporting GPU functionality to market in 2012 at such a reasonable price. The initial thrill is wearing off a bit, but I remain in awe of Apple’s genius – the ability to turn a vision into a functional and beautiful reality and make it available to tens of millions of people. No other company comes close…

  3. Read on TechzTalk that they played games on iPad for over one hour but weren’t able to reach temperatures like 116 degrees as were reported by consumer reports. It got warm but not hot or uncomfortable to hold.

  4. Seems like if the battery is 70% larger, and runs out in the same amount of time, that the new iPad uses 70% more energy, which, assuming the device gives off similar amounts of waste energy, would mean it has to dissipate 70% more waste heat. Of course, it’s warmer.

  5. Every single store I’ve been to… the iPad 3s on display are noticeably warm. Every one. I’ve been to 4 stores. It’s significantly warmer than the iPad 2. No gaming. No anything really. Just surfing the Web and testing iBooks. We’ve all noticed it.

    It’s the quad core GPU, larger processor, additional LEDs, and larger battery. All these contribute in aggregate to increased heat. To me, the increased heat is very real: there’s a simple explanation for it that makes sense. iPad 4 will be thinner and lighter and will have these issues fixed.

  6. Sure, and here is how Consumer Reports did it. Run the battery down, plug it in, now run your graphics intensive game. The combined heat of intense graphics use, with recharge the battery activity=a hotter iPad. Duh… Even the old one was warmer under those conditions. Give me a brake. What a hack by CR.

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