Does the iPad have better pixel density than the MBPr?

FatGuy007

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Original poster
Apr 8, 2012
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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?
 

dmccloud

macrumors 6502a
Sep 7, 2009
991
14
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.
 

pgiguere1

macrumors 68020
May 28, 2009
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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.
 
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gorskiegangsta

macrumors 65816
Mar 13, 2011
1,279
85
Brooklyn, NY
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?
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).
 

terraphantm

macrumors 68040
Jun 27, 2009
3,740
552
Pennsylvania
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.
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.
 

AZREOSpecialist

macrumors 68020
Mar 15, 2009
2,115
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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?
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.
 

FatGuy007

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Original poster
Apr 8, 2012
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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.
In the future, when they are up to there A10 chip, the macbook air would be fine on that, but thats the future
 

hellstorm12345

macrumors newbie
Jun 24, 2012
20
0
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.
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.

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In the future, when they are up to there A10 chip, the macbook air would be fine on that, but thats the future
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.
 

w00t951

macrumors 68000
Jan 6, 2009
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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).
 

Robin Chung

macrumors member
Apr 6, 2010
76
0
Netherlands
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.
 

maflynn

Moderator
Staff member
May 3, 2009
65,424
31,470
Boston
Comparing Macbooks to iPads is comparing apples to oranges. No pun intended.
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.
 

Nozuka

macrumors 68020
Jul 3, 2012
2,272
2,818
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.
 

Dangerous Theory

macrumors 68000
Jul 28, 2011
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UK
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".