Does the iPad have better pixel density than the MBPr?

Discussion in 'MacBook Pro' started by FatGuy007, Aug 13, 2012.

  1. FatGuy007 macrumors 6502

    Apr 8, 2012
    New York
    Really shouldn't mater, but if the iPad has almost equal resolution, 10x less powerful than the MBPr with no lag, how come some MBPr's has UI lag?
  2. dmccloud macrumors 6502a


    Sep 7, 2009
    Anchorage, AK
    Pixel density and resolution are not one and the same.

    iPad 3: 2048-by-1536-pixel resolution at 264 pixels per inch (ppi)
    rMBP: 2880-by-1800 resolution at 220 pixels per inch

    So even though the iPad has a significantly higher pixel density, it's only pushing 3,145,728 pixels, whereas the rMBP is pushing 5,184,000 pixels. That's 2,038,272 more pixels for the rMBP.

    Apple doesn't use the term "Retina Display" to specify a given pixel density. Rather, it refers to a pixel density at which one cannot distinguish individual pixels from the normal viewing range of the device. The shorter the distance between your eyes and the device screen, the higher the pixel density has to be in order to not see individual pixels.
  3. pgiguere1, Aug 13, 2012
    Last edited: Aug 13, 2012

    pgiguere1 macrumors 68020


    May 28, 2009
    Montreal, Canada
    Mainly because the iPad runs a much more lightweight OS running on a different architecture altogether. ARM is generally much more efficient than x86.

    The new iPad also doesn't have almost the same resolution. The rMBP has 65% more pixels which is quite a lot.

    One day ARM processors will be powerful enough for pretty much everything and that will be great since they also give you a much better battery life and produce much less heat.

    Apple has been rumored to test prototype MacBook Airs with ARM processors internally, who knows what will happen with that. That may be the only way to get Retina MBAs with the current form factor while having a very good battery life. That would however also require to rewrite software and would cause fragmentation just like Windows RT vs Windows 8.
  4. gorskiegangsta macrumors 65816


    Mar 13, 2011
    Brooklyn, NY
    Yes, the 3rd gen iPad is 264 PPI while the rMBP is 217 PPI. As for why there's no lag on iPad vs the rMBP, the extra pixels, as well as system architecture, make a difference. While the iPad has the higher PPI, the rMBP has more work to do, to push those pixels forward (40% more pixels, in fact).
  5. terraphantm macrumors 68040

    Jun 27, 2009
    To be completely fair, they're only better on battery/heat because they're 10 years behind x86 in power. If Intel or AMD had deliberately decided to make an x86 CPU with those performance characteristics, I'm sure it'd be nearly as expensive.
  6. AZREOSpecialist macrumors 68020


    Mar 15, 2009
    Nobody here at MacRumors who says they have "lag" is able to reproduce this lag with a video. That's all the proof I need.
  7. FatGuy007 thread starter macrumors 6502

    Apr 8, 2012
    New York
    In the future, when they are up to there A10 chip, the macbook air would be fine on that, but thats the future
  8. hellstorm12345 macrumors newbie

    Jun 24, 2012
    Seriously man, you may have gotten a perfect unit with no lag. Others may not have had the same fortune, or the time to post videos of their lag to prove to just you. Be considerate of the fact that some people do have legitimate concerns about their rMPB speed.


    I sure hope the Air does not have an A10 in the near future. It may be a step up from the A9, but it is a turtle compared to Intel's current Ivy Bridge and upcoming Haswell architectures.
  9. w00t951 macrumors 68000


    Jan 6, 2009
    Pittsburgh, PA
    ARM isn't more efficient. Intel processors are far faster for the energy consumed, but the architectures are aimed at different applications.

    ARM is for low performance, long lasting, low heat applications. It's slow - a 1.3 GHz Exynos 4420 has the name number of cores as an Ivy Bridge quad core ULV processor, but at 1.3GHz the IB will wipe the floor with the Exynos.

    Intel is for high performance applications that are not so constrained in terms of power and heat.

    If you tried making an ARM processor run as quickly (real world usage) as an Intel processor, it would overheat and explode (probably).
  10. gokart mozart macrumors 6502

    Jun 20, 2011
    Comparing Macbooks to iPads is comparing apples to oranges. No pun intended.
  11. Robin Chung macrumors member

    Robin Chung

    Apr 6, 2010
    I have both and prefer the look of the rMBP display. Can't put my finger on it but guess it's a matter of contrast, colors and the extra 5 inches.
  12. maflynn Moderator


    Staff Member

    May 3, 2009
    Agreed, two completely different products, running different operating systems, and intended for different uses.

    tbh, I like my rMBP over my iPad. I use my rMBP everyday where as my iPad is mostly unused, except for reading.
  13. Nozuka macrumors 68020

    Jul 3, 2012
    i actually sold my ipad because i realized i went back to mostly using my notebook. even for webbrowing i felt very restricted..

    now i bought myself the rMBP to get the same smooth text while browsing and i dont regret it any second.

    maybe if they sell a 13'' rMBP i will probably change to that one - i dont really need a laptop this big and would prefer something lighter.
  14. Dangerous Theory macrumors 68000

    Jul 28, 2011
    Because iOS is very lightweight and much more optimised to work with the iPad hardware. Technically you could overcome the slowdowns some people have experienced in the MBPR with brute force but that's an inefficient solution. The OS just needs some work done to it, as evidenced by the fact that only some people have noticed "lag".

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