Printed from

Expert: iPad heat claims overblown, not a real issue

updated 03:15 am EDT, Thu March 22, 2012

Driving 3.1 million pixels a big job

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. He calls the thermographic portraits circulating the web "overblown" and says the extra heat is the natural consequence of increased power.

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.

Soneira, best known for clarifying and codifying the meaning of so-called "Retina" displays, praises the iPhone 4 (and 4S) as being the most power-efficient mobile device Apple makes, due to its exclusive use of Low Temperature Poly Silicon (LTPS), a much more power-efficient display than the Amorphous Silicon used in both the iPad 2 and the latest model. 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.

He tested the new iPad by running it at maximum brightness and found that the battery was exhausted in 5.8 hours, 20 percent less time than a similar test with the iPad 2, indicating that the increased resolution can also generate more heat, which contributes to battery drain. Soneira also found that maximum brightness consumed 65 percent of the total power used by the device, stressing the importance of both heat-generation and power-consumption in test results. Tests with the brightness at normal levels (middle brightness) showed the new iPad almost exactly matching the previous model, proving heat generation of the display can play a major role in the device's efficiency.

The combined extra heat of the display, the more powerful processor and graphics chip and the heat generated by the battery itself would not be able to sustain the new iPad for long if the heat-dispersal capabilities of the device were not up to par. Apple has issued a statement saying the new iPad operates within the devices' temperature specifications, but users may want to be way of covering the back of the device with a form-fitting enclosure that doesn't also promote heat dissipation.

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.

LED backlight spectrum compared

By Electronista Staff
Post tools:




  1. MadGoat

    Fresh-Faced Recruit

    Joined: Feb 2008


    Fandroids won't let it go that easily

    No matter how many experts you bring in, they will still make it look like it's a bigger issue than it really is.

    Comment buried. Show
  1. macnnoel

    Fresh-Faced Recruit

    Joined: Feb 2005


    "Expert: iPad heat claims overblown, not a real is


  1. Jeronimo2000

    Forum Regular

    Joined: Aug 2001



    Someone with some common sense. Every time a new iDevice hit the market, the media gets all crazy to find *some* fault with it. Oooh, it gets warm. Apple is doomed.

  1. Eriamjh

    Addicted to MacNN

    Joined: Oct 2001



    "but users may want to be way of covering the back of the device with a form-fitting enclosure"

    I think you mean WARY of covering the back....

  1. global.philosopher

    Fresh-Faced Recruit

    Joined: Sep 2010


    Samsung trolling coming soon

    Samsung won't be able to help themselves....just wait and see.

  1. sribe

    Fresh-Faced Recruit

    Joined: Jan 2003


    high-school physics

    "...proving heat generation of the display can play a major role in the device's efficiency."

    No, dumbass, heat generation is the product and measure of inefficiency.

  1. iphonerulez

    Dedicated MacNNer

    Joined: Nov 2008


    Not going to stop the iHaters

    because the haters gotta hate anything that comes from Apple and blow any minor issues out of proportion. We'll see how well other tablet vendors do that start using HD displays in thin-case tablets manage to handle the heat dissipation issue. If the iPad has 98% good points, the haters are going to dwell on the 2% bad points. In the end, Apple is still going to sell tens of millions of iPads this year and the Heatgate Chronicles aren't going to change a thing.

    Comment buried. Show
  1. simon42

    Fresh-Faced Recruit

    Joined: Apr 2010


    Apple got lazy

    They stuck with 45nm. So they will be outdated long before new new iPad comes. Of course, relying on Samsung for a better process wasn't going work, was it? At least the profit margins are intact - but this iPad will be remembered as a sub-par Apple product (which is still a pretty good product and most probably still a sales class leader).

  1. testudo

    Forum Regular

    Joined: Aug 2001


    Re: Finally

    Someone with some common sense. Every time a new iDevice hit the market, the media gets all crazy to find *some* fault with it. Oooh, it gets warm. Apple is doomed.

    And every time someone mentions anything actually wrong with an Apple product, we hear how it's overblown from the fanboy crowd, and anyone who says its overblown is a 'voice of reason' or has 'common sense'. Amazing how those who agree with your opinion are the 'correct' ones.

  1. testudo

    Forum Regular

    Joined: Aug 2001



    The "problem" has been stated that the iPad gets far warmer than the previous version. I've not seen people say "Oh, it's running hot, there must be an issue with the battery. It's going to explode! I've burned my hands! Sue, sue, sue!". Just "It's running hot. This could be a problem." And it could be. Not with the device, but with the users of the device. Some might find it uncomfortable to hold because of the heat dissipation. Or that using the wrong case could cause it to overheat because you're not letting the heat dissipate.

    But why actually discuss anything of substance. Just discount the whole subject matter. And when people complain their iPads have died and the Apple genius says its because it over heated, I'm sure you'll explain how they should have known not to put a non-heat-dissipating case on it because it was all over the news (yes, the news you don't want reported because its overblown). You know, how you tell people that had scratched iPod screens it's their fault for putting their ipods in their pockets at all, or without screen protection. Not apple's fault. Nope.

Login Here

Not a member of the MacNN forums? Register now for free.


Network Headlines


Most Popular


Recent Reviews

Seagate Wireless

It seems like no matter how much internal storage is included today's mobile devices, we, as users, will always find a way to fill the ...

Lenovo Yoga Tablet 2 (Android, 10.1-inch)

Lenovo is building a bigger name for itself year after year, including its devices expanding beyond desktop computers. The company's l ...

Brother HL-L8250CDN Color Laser Printer

When it comes to selecting a printer, the process is not exactly something most people put a lot of thought into. Printers are often t ...



Most Commented


Popular News