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FatPuppy

macrumors 68000
Original poster
Jul 14, 2012
1,709
151
Devs will start updating their apps for 64bit, would this have an impact on older devices in terms of performance? I am planning to buy an iphone 5 and I don't want it to start to lag after 1 year like the iphone 4.
 

Tarrant64

macrumors member
Mar 10, 2006
47
20
Only if you're gaming really. Newer apps maybe in the next year or so could see some minor issues but I can't see it being all that bad. The 32-bit processor will just run the 32-bit versions of the app is all.

The real issue can potentially come from anyone who develops a 64-bit only app (not sure why anyone would do this). You'll basically have an iPhone 5 that runs 32-bit apps great, and a 64-bit iPhone 5s that runs it even better.
 

thejadedmonkey

macrumors G3
May 28, 2005
9,188
3,357
Pennsylvania
No developer in their right mind would make a 64bit app right now, as it will give no performance improvement (the system doesn't even max out a 32bit system yet) and it will limit the audience to iPhone 5s users only.

The only way any sane developer would do this is if Apple pushes out a "64bit App" section in the iTunes store.
 

Krevnik

macrumors 601
Sep 8, 2003
4,100
1,309
No developer in their right mind would make a 64bit app right now, as it will give no performance improvement (the system doesn't even max out a 32bit system yet) and it will limit the audience to iPhone 5s users only.

The only way any sane developer would do this is if Apple pushes out a "64bit App" section in the iTunes store.

The binaries are fat binaries, so you would be compiling for both targets. And there is a benefit to recompiling for both platforms now: Your app will take advantage to the ISA changes in A64 which will result in a speed boost in 64-bit mode. Things like additional registers when running in 64-bit mode.

For some devs, it will just be hitting a button and running a build. For others, there's a bit more work to do to make it 64-bit clean so it can compile for both (I've seen the coding practices that make that potentially ugly, ugh).
 

C DM

macrumors Sandy Bridge
Oct 17, 2011
51,392
19,459
I don't think that's the case.

You can target iOS 6 and still offer 64-bit, it's just iOS 5 that you can't target.
I wonder why that would be. Realistically the only device (so far) that has 64-bit support is the iPhone 5S, and that won't support a version of iOS less than 7. I guess the two don't have to be connected necessarily, but it would make sense for them to be in most cases.
 

Daveoc64

macrumors 601
Jan 16, 2008
4,075
95
Bristol, UK
I wonder why that would be. Realistically the only device (so far) that has 64-bit support is the iPhone 5S, and that won't support a version of iOS less than 7. I guess the two don't have to be connected necessarily, but it would make sense for them to be in most cases.

The point is that the App will still be able to work on iOS 6 devices such as the iPhone 3GS, while supporting iOS 7 and running in 64-bit mode on iPhone 5s.

If a developer wants/needs to target iOS 5 still (for the original iPad) they will be unable to offer 64-bit support.
 

FatPuppy

macrumors 68000
Original poster
Jul 14, 2012
1,709
151
I wonder why that would be. Realistically the only device (so far) that has 64-bit support is the iPhone 5S, and that won't support a version of iOS less than 7. I guess the two don't have to be connected necessarily, but it would make sense for them to be in most cases.

It's apple, can't you see that they just want money. Almost all of they apps require ios 6 and some of them even 6.1. There are some famous apps that once ios 6 came out, they dropped support for ios 5
 

thejadedmonkey

macrumors G3
May 28, 2005
9,188
3,357
Pennsylvania
The binaries are fat binaries, so you would be compiling for both targets. And there is a benefit to recompiling for both platforms now: Your app will take advantage to the ISA changes in A64 which will result in a speed boost in 64-bit mode. Things like additional registers when running in 64-bit mode.

For some devs, it will just be hitting a button and running a build. For others, there's a bit more work to do to make it 64-bit clean so it can compile for both (I've seen the coding practices that make that potentially ugly, ugh).

My understanding is that in order to take advantage of the additional registers, you need more RAM too. As I recall from when Windows Vista came out, on devices with less than 4gb of RAM it was actually faster to run the 32 bit version as there was less overhead. Please correct me if I'm mistaken.
 

Joaolx

macrumors member
Aug 31, 2013
47
2
Europe
Like Apple said, they were think ahead. In a year or so apps, big ones or new ones,will have support for 64bit and then the next iPhones and probably iPads will already be able to take advantage of 64bit without need to update again. Everyone is complaining that it will take years to move to 64bit just like pc, but this way when new hardware comes out that needs 64bit comes out it already has apps to run on. And the guys that showed off IB3 said it took to 2 hours to make it run in 64bit so maybe it might not be a slow process like it was on pc.
 

WordMasterRice

macrumors 6502a
Aug 3, 2010
734
100
Upstate NY
My understanding is that in order to take advantage of the additional registers, you need more RAM too. As I recall from when Windows Vista came out, on devices with less than 4gb of RAM it was actually faster to run the 32 bit version as there was less overhead. Please correct me if I'm mistaken.

Yea you are mistaken on that point. The 64-bit stuff on Vista had a lot to do with the terribleness of Vista compared to 64-bit directly. More registers actually means you rely less on RAM (or cache more than likely since it's unlikely that you would cache out from a register directly to memory). The difference is minute but doubling the registers is a big deal.
 
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