Dual core or Quad core processor?

[yeah]

I like the idea of that dual core Cortex A-15 with it's low power features and speed increases linked with a PowerVR G6 graphics which is like 20 times faster than the current iPad2 GPU.
That would be an awesome beast.

My cotton U.S. paper is screaming:

A-15 Cortex Quad-Core processor
1GB or more RAM
Better battery
Quad-Core GPU
4G LTE

 

[MythicFrost]

I'm really hoping they go with a quad-core processor. Just look at the graphics in GlowBall for Tegra 3: Part 1, Part 2

I'm no expert, so I may be wrong, but dynamic lighting, and all those effects appear to require it.

That aside, if the iPad 3 does get a retina display which I'm sure it will, if they stay with the SGX543 Apple will need at the very least six of them. Hopefully it'll have a PowerVR 600 series GPU though.

 

[Awfisch]

Quad Core

So far, the ASUS Eee Pad Transformer Prime has been the only quad core tablet that has managed to create a power efficient device. Apple is known for their legendary battery life, and so the only I can see them creating a quad core device, is if they manage to create a power efficient A6 chip. The iPad 2 handles everything that is thrown at it using a dual core processor, and so the only reason I could see Apple using a quad core is for handling the processing of a retina display (which would be needed).

As a former avid Android user, I get so sick of the specs race. I think that Apple hits it on the mark when they make their devices, because deep down, Apple is a software company. Its all about software. These new Android phones have ridiculous power potential, but they fall short because Android isn't optimized for each device. The same goes for battery life.

This has kind of turned into an anti-Android post but basically, if Apple has the ability to create a power efficient processor, then they will use it because it will be needed for a retina display.

 

[Jordom115]

So far, the ASUS Eee Pad Transformer Prime has been the only quad core tablet that has managed to create a power efficient device. Apple is known for their legendary battery life, and so the only I can see them creating a quad core device, is if they manage to create a power efficient A6 chip. The iPad 2 handles everything that is thrown at it using a dual core processor, and so the only reason I could see Apple using a quad core is for handling the processing of a retina display (which would be needed).

As a former avid Android user, I get so sick of the specs race. I think that Apple hits it on the mark when they make their devices, because deep down, Apple is a software company. Its all about software. These new Android phones have ridiculous power potential, but they fall short because Android isn't optimized for each device. The same goes for battery life.

This has kind of turned into an anti-Android post but basically, if Apple has the ability to create a power efficient processor, then they will use it because it will be needed for a retina display.

Well put. I know what ever Apple has decided to use, it will run beautifully and likely blow everyone away just like the first two iPads. It's fun to make educated (or uneducated) guesses until we know for sure next month.

It's refreshing to see an Android user (or former user) who actually acknowledges some of Androids downfalls.

I am not one to blindly criticize Android, but many of my Android loving friends like to criticize me for being so completely Apple-centric. I always try to keep my cool and explain that it's all based on opinion, both OS's have their pros and cons. All I ever hear about is how Apple is so locked down and restricted... I get that it's not open source, but I've never experienced any notable problems. Meanwhile in Android land, I hear stories about all the different versions of the OS and various bugs and issues associated with individual handsets... blah.

Anyway, I don't really have a point. It's just frustrating. Thank you for your post.

I am irrationally excited about the next iPad.

 

[eaf7s]

So far, the ASUS Eee Pad Transformer Prime has been the only quad core tablet that has managed to create a power efficient device. Apple is known for their legendary battery life, and so the only I can see them creating a quad core device, is if they manage to create a power efficient A6 chip. The iPad 2 handles everything that is thrown at it using a dual core processor, and so the only reason I could see Apple using a quad core is for handling the processing of a retina display (which would be needed).

As a former avid Android user, I get so sick of the specs race. I think that Apple hits it on the mark when they make their devices, because deep down, Apple is a software company. Its all about software. These new Android phones have ridiculous power potential, but they fall short because Android isn't optimized for each device. The same goes for battery life.

This has kind of turned into an anti-Android post but basically, if Apple has the ability to create a power efficient processor, then they will use it because it will be needed for a retina display.

Excellent post. This is why I've gone from an Apple skeptic to ALL of my devices being Apple--the tailoring of every piece of software to each meticulously created piece of hardware, and the seamless and effortless integration between all devices. And knowing that all I have to do for support is make a Genuis Bar appointment (honestly, they have taken care of every problem I've ever had, for free). A friend and Android fanatic has recently had some hardware issues on his HTC whatever, and it's been weeks now of angry phone calls and forms to get the simplest problem addressed. I had a similar issue with my iPhone and ten minutes after walking into the Apple store I walked out with a completely new (refurb, whatever, same warranty) phone that hasn't had an issue since.

All that said, I have a sneaking suspicion that they are going to go dual-core on the next iPad and everyone will bitch and moan, and experience no noticeable issues . Apple don't make a habit of releasing products that don't work like a charm.

 

[TheSuperSteve]

Like many, I want a quad-core but deep down I think everyone knows we're getting a better dual-core. Doesn't matter as long as the full product lives up to Apple's usual quality. My ol' iPad 1 is feeling quite slow and I use it for taking notes at my university. So I can't wait for the iPad 3. It'll be massively useful to have a much faster device.

My only concern is that I hope all the iOS devs get their act together and start updating their iPad apps to retina quality as soon as possible.

 

[0098386]

I don't think I've hit a point whilst using my iPad 2 that I thought "I wish this was faster" or had stuttered or lagged. I use mine as a laptop replacement (for documents+browsing, Garageband and games) so I like to think I push it too.

This thing needs a quad core CPU?

 

[WLS]

More leaks continue to say it will be a quad core A6. Will that be the Cortex A9?
https://www.macrumors.com/2012/02/13/ipad-3-announcement-on-march-7th-with-quad-core-and-4g-lte/

 

[IscariotJ]

More leaks continue to say it will be a quad core A6. Will that be the Cortex A9?
https://www.macrumors.com/2012/02/13/ipad-3-announcement-on-march-7th-with-quad-core-and-4g-lte/

I reckon so, everything I've read regarding chips based on the Cortex A15 suggests that they won't be out until later on in 2012 ( this, for example.

 

[ThatsMeRight]

I reckon so, everything I've read regarding chips based on the Cortex A15 suggests that they won't be out until later on in 2012 ( this, for example.

Samsung is widely expected to introduce devices later this month, in Barcelona, with chips based on the Cortex A15 architecture. I even read an article where a Samsung representative confirmed it, but I can't find it back (I'll let you know when I do).

If Samsung is already busy with producing chips based on the Cortex A15 architecture, than it is very well possible they are also producing chips for Apple with the Cortex A15 architecture.

Again, I'd rather have a dual-core 1 GHz processor based on the Cortex A15 architecture, than a quad-core 1 GHz processor based on the Cortex A9 architecture.

The first one (Cortex A15, dual-core) benefits all software running on the iPad (including iOS itself). The second one (Cortex A9, quad-core) would only benefit iOS itself and apps that are specifically build for four cores (which is very hard).

 

[andiwm2003]

Samsung is widely expected to introduce devices later this month, in Barcelona, with chips based on the Cortex A15 architecture. I even read an article where a Samsung representative confirmed it, but I can't find it back (I'll let you know when I do).

If Samsung is already busy with producing chips based on the Cortex A15 architecture, than it is very well possible they are also producing chips for Apple with the Cortex A15 architecture.

Again, I'd rather have a dual-core 1 GHz processor based on the Cortex A15 architecture, than a quad-core 1 GHz processor based on the Cortex A9 architecture.

The first one (Cortex A15, dual-core) benefits all software running on the iPad (including iOS itself). The second one (Cortex A9, quad-core) would only benefit iOS itself and apps that are specifically build for four cores (which is very hard).

+1. I think it would make the iPad3 more future proof to have a faster dual core because it will run individual apps/tasks fast in the future. Quad Core only benefits specialized applications that not that many users need.

 

[IscariotJ]

Samsung is widely expected to introduce devices later this month, in Barcelona, with chips based on the Cortex A15 architecture. I even read an article where a Samsung representative confirmed it, but I can't find it back (I'll let you know when I do).

I'd be interested to read that; the article I linked to is the only one I could find. Articles on the A15 are scarce, which is a tad annoying....

I'd be happy to see the A6 based on the Cortex A15, especially if it's based on the design that includes the A7 pairing....

 

[ThatsMeRight]

I'd be interested to read that; the article I linked to is the only one I could find. Articles on the A15 are scarce, which is a tad annoying....

I'd be happy to see the A6 based on the Cortex A15, especially if it's based on the design that includes the A7 pairing....

I was unable to find the article again, unfortunately. Today, however, I stumbled upon something amazing. Engadget posted an article where Texas Instrument's OMAP 5's dual-core Cortex A15 chip was competing against a quad-core Cortex A9 chip.

http://www.engadget.com/2012/02/23/omap-5s-dual-a15-cores-wipe-the-floor-with-four-a9s/#continued

OMAP 5 - Cortex A15 (next-gen architecture) - Dual-Core clocked at 800 MHz
versus
Unspecified chip - Cortex A9 (archicture used for A5 chip) - Quad-Core clocked at 1.3 GHz

The results are striking and after you all have read this post, I'm sure you all want a dual-core A6 chip based on the Cortex A15 architecture at 1 GHz each, rather than a quad-core A6 chip based on the Cortex A9 architecture at 1 GHz each.

Remember, we are now comparing a 800 MHz dual-core Cortex A15 processor, against a 1.3 GHz quad-core Cortex A9 processor.

Comparing the processors

Test: loading twenty graphically intense HTML5 pages, while playing a MP3 file and downloading a video file.
Dual-Core Cortex A15 (800 MHz): 95 seconds in total
Quad-Core Cortex A9 (1.3 GHz): 201 seconds in total

That's amazing! Remember, the iPad 3 is rumoured to have a quad-core Cortex A9 1 GHz processor. I sincerely hope that the A5X processor is real, and turns out to be a dual-core Cortex A15 1 GHz processor.

-------------------------------------------------------------
Now, of course we were talking about the release date and when these things are ready. I've also found an article on Engadget that's about one year old.

http://www.engadget.com/2011/02/07/ti-announces-omap-5-two-high-performance-and-two-low-power-core/

The newest article I could find regarding the OMAP 5 is this one:

http://pinoytutorial.com/techtorial...beastly-specs-for-tablets-ultrabooks-on-2013/

It isn't too far of from its original schedule: second half or 2012, or at its latest point early 2013.

There's a small difference however. We all expect Apple to announce a quad-core Cortex A9 processor at 1 GHz, or a dual-core Cortex A15 processor at 1 GHz. Samsung and Texas Instruments are talking about 2 GHz dual-core Cortex A15 processors.

I don't see Apple going to 2 GHz - especially not with battery life in mind. I see them staying at 1 GHz this year, and if that's the case, than it is very well possible Apple gives us an A6/A5X chip with the Cortex A15 architecture.

Assuming they go for a dual-core 1 GHz Cortex A15 processor, than in 2013 they could do either one of these two things:

- Quad-Core 1 GHz Cortex A15 processor (more cores)
- Dual Core 1.1-2 GHz Cortex A15 processor (higher clockspeeds)

---------------------------------------------------
To be honest, the more I start to think about it, the more I believe Apple is actually going to introduce an A6 / A5X processor with the Cortex A15 architecture.

Think about it.

If they are going to stay with the Cortex A9 architecture (like rumoured [quad-core Cortex A9]), than that would give them difficulties next year. Apple is trying to compete with both hardware and software (people say Apple doesn't compete on hardware, but the opposite is true).

Why would it give Apple difficulties next year if they are releasing a quad-core Cortex A9 processor? Simply because next year they just have to switch to the Cortex A15 architecture - it's a necessity. They just can not stick with the Cortex A9 architecture in 2013. In 2013 they have to switch to the Cortex A15 architecture - the whole market is moving to the Cortex A15 architecture.

So, what would happen if Apple indeed released the following:

- A6 chip: a 1 GHz quad-core processor based on the Cortex A9 architecture

Well, than in 2013, when it's necessary to switch from architecture, they would have to come up with this:

- A7 chip: a 1 GHz quad-core processor on the Cortex A15 architecture

It needs to be a quad-core processor (they can't go back to dual-core). And it's too complicated and simply too risky to change from architecture and double the amount of cores (and perhaps changing from 32nm to, like what, 21 nm?).
That is why, I believe Apple is going to do this:

- A6 chip (or A5X, if you'd like): a 1 GHz dual-core processor based on the Cortex A15 achitecture.

And than in 2013, they could do the following things:

- A7 chip: a higher clocked dual-core processor based on the Cortex A15 architecture
- A7 chip: a 1 GHz quad-core processor based on the Cortex A15 architecture



-----------------
Pfew, quite a story. I hope you guys understand what I'm trying to say, haha.

 

[Jordom115]

I was unable to find the article again, unfortunately. Today, however, I stumbled upon something amazing. Engadget posted an article where Texas Instrument's OMAP 5's dual-core Cortex A15 chip was competing against a quad-core Cortex A9 chip.

http://www.engadget.com/2012/02/23/omap-5s-dual-a15-cores-wipe-the-floor-with-four-a9s/#continued

OMAP 5 - Cortex A15 (next-gen architecture) - Dual-Core clocked at 800 MHz
versus
Unspecified chip - Cortex A9 (archicture used for A5 chip) - Quad-Core clocked at 1.3 GHz

The results are striking and after you all have read this post, I'm sure you all want a dual-core A6 chip based on the Cortex A15 architecture at 1 GHz each, rather than a quad-core A6 chip based on the Cortex A9 architecture at 1 GHz each.

Remember, we are now comparing a 800 MHz dual-core Cortex A15 processor, against a 1.3 GHz quad-core Cortex A9 processor.

Comparing the processors

Test: loading twenty graphically intense HTML5 pages, while playing a MP3 file and downloading a video file.
Dual-Core Cortex A15 (800 MHz): 95 seconds in total
Quad-Core Cortex A9 (1.3 GHz): 201 seconds in total

That's amazing! Remember, the iPad 3 is rumoured to have a quad-core Cortex A9 1 GHz processor. I sincerely hope that the A5X processor is real, and turns out to be a dual-core Cortex A15 1 GHz processor.

-------------------------------------------------------------
Now, of course we were talking about the release date and when these things are ready. I've also found an article on Engadget that's about one year old.

http://www.engadget.com/2011/02/07/ti-announces-omap-5-two-high-performance-and-two-low-power-core/

The newest article I could find regarding the OMAP 5 is this one:

http://pinoytutorial.com/techtorial...beastly-specs-for-tablets-ultrabooks-on-2013/

It isn't too far of from its original schedule: second half or 2012, or at its latest point early 2013.

There's a small difference however. We all expect Apple to announce a quad-core Cortex A9 processor at 1 GHz, or a dual-core Cortex A15 processor at 1 GHz. Samsung and Texas Instruments are talking about 2 GHz dual-core Cortex A15 processors.

I don't see Apple going to 2 GHz - especially not with battery life in mind. I see them staying at 1 GHz this year, and if that's the case, than it is very well possible Apple gives us an A6/A5X chip with the Cortex A15 architecture.

Assuming they go for a dual-core 1 GHz Cortex A15 processor, than in 2013 they could do either one of these two things:

- Quad-Core 1 GHz Cortex A15 processor (more cores)
- Dual Core 1.1-2 GHz Cortex A15 processor (higher clockspeeds)

---------------------------------------------------
To be honest, the more I start to think about it, the more I believe Apple is actually going to introduce an A6 / A5X processor with the Cortex A15 architecture.

Think about it.

If they are going to stay with the Cortex A9 architecture (like rumoured [quad-core Cortex A9]), than that would give them difficulties next year. Apple is trying to compete with both hardware and software (people say Apple doesn't compete on hardware, but the opposite is true).

Why would it give Apple difficulties next year if they are releasing a quad-core Cortex A9 processor? Simply because next year they just have to switch to the Cortex A15 architecture - it's a necessity. They just can not stick with the Cortex A9 architecture in 2013. In 2013 they have to switch to the Cortex A15 architecture - the whole market is moving to the Cortex A15 architecture.

So, what would happen if Apple indeed released the following:

- A6 chip: a 1 GHz quad-core processor based on the Cortex A9 architecture

Well, than in 2013, when it's necessary to switch from architecture, they would have to come up with this:

- A7 chip: a 1 GHz quad-core processor on the Cortex A15 architecture

It needs to be a quad-core processor (they can't go back to dual-core). And it's too complicated and simply too risky to change from architecture and double the amount of cores (and perhaps changing from 32nm to, like what, 21 nm?).
That is why, I believe Apple is going to do this:

- A6 chip (or A5X, if you'd like): a 1 GHz dual-core processor based on the Cortex A15 achitecture.

And than in 2013, they could do the following things:

- A7 chip: a higher clocked dual-core processor based on the Cortex A15 architecture
- A7 chip: a 1 GHz quad-core processor based on the Cortex A15 architecture



-----------------
Pfew, quite a story. I hope you guys understand what I'm trying to say, haha.

Nice post. I really hope you're right but I am very concerned that indeed the A6 will be a quad 1Ghz A9. -- I agree that Apple will need to adopt A15 next year but Apple may have a quad core A15 in the road map for the iPad4. I hope I am wrong about this but with all the leaks about the Quad core, I have started to believe it's the only way Apple could have gone this time around. I would think Apple would have started leaking dual core information by now to counter all the quad core rumors. The average consumer just does not get that a dual core can be better than a quad core. Apple knows this. Unfortunately it might be one of the main reasons they will go with the Quad A9.

I really hope I'm wrong about this.

 

[falcora]

I am saying that the number of cores is less relevant with Grand Central Dispatch. If a program can benefit from multi-processing, iOS (and Mac OS X 10.6+) abstracts core-awareness away. A program can be written in "blocks" that GCD will balance across cores. It does require skill to write asynchronous code that runs well, but not as much as it would with explicit core-aware threading.

Now a programmer can write for efficiency and let the system distribute the load across what processing resources are available, and when extra cores are unneeded, they can be down-clocked or put to sleep to conserve power.

But this is not to say that I personally think they are going quad. iPad is not targeted toward breath-taking performance but toward the broader consumer market that mostly does not care about wowspecs. This coming iPad will probably improve the GPUs but leave headroom for CPU upgrades later. If they massively increase display resolution, the GPUs will take the heaviest workload. And RAM, they almost have to go to a gig of that.

Exactly. If a program is already written correctly to take advantage of the dual core A5 on iPad 2 and iPhone 4S, then it will already be optimized for a quad core A6 (or A5X or whatever)

 

[IscariotJ]

I was unable to find the article again, unfortunately. Today, however, I stumbled upon something amazing. Engadget posted an article where Texas Instrument's OMAP 5's dual-core Cortex A15 chip was competing against a quad-core Cortex A9 chip.

That's stunning, much appreciated....

 

[WLS]

From the Engadget article clearly the dual core cortex A15 beats the quad core cortex A9 easily. I don't see where that is a problem we need to argue about because it is likely that the A15's were not available in quantity and low cost when Apple was finalizing the specs for the A5X. The quad core cortex A9 with improved GPU will be powerful enough for the iPad3 and as been pointed out if the code is written to comply with Grand Central Dispatch then the extra cores will be used effectively automatically. Yes Apple will have to go with the cortex A15 next year but they can then go with the dual core A15 version since that is more powerful than the current quad core cortex A9 and save going to a quad core A15 for yet another generation. Apple seldom goes with a cutting edge technical choice preferring to use a tested and proven solution. Throwing in 1GB RAM which is needed for the graphics will give a iPad 3 which will be pretty darn impressive for most people.

 

[ThatsMeRight]

From the Engadget article clearly the dual core cortex A15 beats the quad core cortex A9 easily. I don't see where that is a problem we need to argue about because it is likely that the A15's were not available in quantity and low cost when Apple was finalizing the specs for the A5X. The quad core cortex A9 with improved GPU will be powerful enough for the iPad3 and as been pointed out if the code is written to comply with Grand Central Dispatch then the extra cores will be used effectively automatically. Yes Apple will have to go with the cortex A15 next year but they can then go with the dual core A15 version since that is more powerful than the current quad core cortex A9 and save going to a quad core A15 for yet another generation. Apple seldom goes with a cutting edge technical choice preferring to use a tested and proven solution. Throwing in 1GB RAM which is needed for the graphics will give a iPad 3 which will be pretty darn impressive for most people.

They can't do that. If they go quad-core Cortex A9 now, and move to Cortex A15 architecture next year, than next year they must give us a quad-core Cortex A15. Otherwise they will break all apps that are going to rely on the use of all four cores.

Apple seldom goes with a cutting edge technical choice preferring to use a tested and proven solution.

Actually, incorrect. Apple was very early with moving to the Cortex A8 architecture. Apple uses Intel chips in their Macs that might not be flawless (like was discovered last year). Apple was among the first to move to a dual core processor in a tablet. Apple was the first to move to a high-end GPU with the A5 chip.

Apple likes you to think they do not care about the hardware, but they do very much. Before the iPhone 4, Apple said front facing cameras were useless. When the iPhone 4 was announced, instead of talking about the front facing camera allowing for Skype and stuff like that, they were talking about FaceTime.

Again, Apple likes you to think hardware doesn't really matter to them, but it does very much.

 

[borgqueenx]

I just hope it will be monster! 6 series gpu, a15, 128gb, retina, 12h battery, oh how we can dream. If it all comes true i also hope it ships with some sunglasses to protect my eyes against the intense power and beauty

 

[ThatsMeRight]

I just hope it will be monster! 6 series gpu, a15, 128gb, retina, 12h battery, oh how we can dream. If it all comes true i also hope it ships with some sunglasses to protect my eyes against the intense power and beauty

Haha, don't expect too much though.

There's no garantuee anything we discussed here is actually going to happen. What I try to do, is to expect as little as possible. If the update is not big, than you are not disappointed. If the update is big, you will get excited.

 

[WLS]

They can't do that. If they go quad-core Cortex A9 now, and move to Cortex A15 architecture next year, than next year they must give us a quad-core Cortex A15. Otherwise they will break all apps that are going to rely on the use of all four cores.


Again, Apple likes you to think hardware doesn't really matter to them, but it does very much.

I admit I am not the expert here but you have not made your case as to why after going quad core you can't go back to dual. The A15 will be clearly faster even as a dual core. If the code is done correctly it should be core independent as to numbers. Dual core should not be any difference than quad once you write for multiple cores.

 

[ThatsMeRight]

I admit I am not the expert here but you have not made your case as to why after going quad core you can't go back to dual. The A15 will be clearly faster even as a dual core. If the code is done correctly it should be core independent as to numbers. Dual core should not be any difference than quad once you write for multiple cores.

It's simple. Apple can NOT expect from developers that they are the best in coding and do everything as efficiently as possible.

If Apple puts in a quad-core processor this year, than they should never go back to dual-core - even when changing from architecture. There are going to be developers who are going to decide to make use of all four cores. Sure, good developers make it like that, that an app can work just as good on two cores... but that's not always possible.

A developer who is going to develop (heavy) apps a device with a quad-core processor in mind, is going to make use of all these four cores. Perhaps the developer even makes it so. For example, a game developer can make it like this:

- one core for setting up the game world using maximum power (100%)
- another core for ensuring smooth controls / user (using maximum power)
- the third core for Artificial Intelligence (maximum power)
- the fourth cor for moving objects (maximum power)

What do you think what happens if Apple suddenly removes two cores the next year (so dual-core again)? The first and second core definitely won't be able to take over - the Cortex A15 architecture doesn't give you 100% more performance. Now you have like 400% (simple explanation), and a dual-core Cortex A15 (perhaps clocked higher), will give you 300%. That's still not enough.

As soon as you give a developer four cores, you just can't take that away later.

Sure, Apple can try to 'simulate' that there are four cores - but that simply won't work for all apps.

 

[Sydde]

It's simple. Apple can NOT expect from developers that they are the best in coding and do everything as efficiently as possible.

If Apple puts in a quad-core processor this year, than they should never go back to dual-core - even when changing from architecture. There are going to be developers who are going to decide to make use of all four cores. Sure, good developers make it like that, that an app can work just as good on two cores... but that's not always possible.

A developer who is going to develop (heavy) apps a device with a quad-core processor in mind, is going to make use of all these four cores. Perhaps the developer even makes it so. For example, a game developer can make it like this:

- one core for setting up the game world using maximum power (100%)
- another core for ensuring smooth controls / user (using maximum power)
- the third core for Artificial Intelligence (maximum power)
- the fourth cor for moving objects (maximum power)

What do you think what happens if Apple suddenly removes two cores the next year (so dual-core again)? The first and second core definitely won't be able to take over - the Cortex A15 architecture doesn't give you 100% more performance. Now you have like 400% (simple explanation), and a dual-core Cortex A15 (perhaps clocked higher), will give you 300%. That's still not enough.

As soon as you give a developer four cores, you just can't take that away later.

Sure, Apple can try to 'simulate' that there are four cores - but that simply won't work for all apps.

Sorry, but you are way off base here. Developers are moving to GCD just so that this will not be an issue. Assigning threads specifically to cores is very difficult in the first place, it is much easier to use GCD and let the OS distribute the load, because the OS will know the capabilities of the machine, so why should the app have to?

If you could put all your work onto all the cores, the OS would simply have to break into one of your threads to do the stuff it does in the background (quite a lot, really), and you the programmer cannot guess which thread that will be, so how do you calculate the load balance?

GCD is only slightly different from simple (!) multi-threading, easier really, and it makes the code core-agnostic. Any programmer that would go to the pain and frustration of working directly with the cores for optimal performance would be a fool. Why would you write an app that performs beautifully only on iPad 3 but stutters on the 2 or 1, of which there will still be very many, when it is far less work to make it run its very best on all three models?

There is no reason for Apple to no be able to go back to dual core after having 4. I mean, look at the diversity in core count across the Mac lineup, and they all do quite well on single-app-binary distributions.

 

[ThatsMeRight]

Sorry, but you are way off base here. Developers are moving to GCD just so that this will not be an issue. Assigning threads specifically to cores is very difficult in the first place, it is much easier to use GCD and let the OS distribute the load, because the OS will know the capabilities of the machine, so why should the app have to?

You just can't assume developers work like that. You are saying that developers are moving to GCD. So that means a lot of developers are not yet working like this.

If you could put all your work onto all the cores, the OS would simply have to break into one of your threads to do the stuff it does in the background (quite a lot, really), and you the programmer cannot guess which thread that will be, so how do you calculate the load balance?

GCD is only slightly different from simple (!) multi-threading, easier really, and it makes the code core-agnostic. Any programmer that would go to the pain and frustration of working directly with the cores for optimal performance would be a fool. Why would you write an app that performs beautifully only on iPad 3 but stutters on the 2 or 1, of which there will still be very many, when it is far less work to make it run its very best on all three models?

Who says the developer wants to get his or her app available on the iPad 2 and iPad 1? I don't think is a good argument. Developers make very different decisions and it is not for you to decide that a developer must make an app with the iPad 2 and 1 in mind.

There is no reason for Apple to no be able to go back to dual core after having 4. I mean, look at the diversity in core count across the Mac lineup, and they all do quite well on single-app-binary distributions.

A Mac is in no way comparable to the iPad. There are literally tens of thousands of different PC configurations, and developers know this. In March, there are only three iPads with three different pieces of hardware. Than a developer can say "I'm going to make an app that's going to make use of all four cores (if the A6 has 4 cores) and ignore the iPad 2 and iPad 1. I'm going to give the iPad 3 app the best performance possible. All four cores will be used at 100%" - and than his app will be broken on the iPad 4 if they go back to dual core, or will at least run at lower performance.

It's all about the apps on iPad. Apple doesn't want such a situation to happen: apps running worse on their newest devices compared to their older devices - even if it's only ONE app. Apple engineers and executives are perfectionists - they won't allow this to happen.

Once they go to four cores, they will never go back to two cores - there are too many risks with bad app compatibility and you just CAN NOT assume developers are developing as efficient as possible. You can't assume they are using GCD. You can't assume that there are zero developers that are only going to focus on ONE device instead of multiple devices.

 

[WLS]

It's simple. Apple can NOT expect from developers that they are the best in coding and do everything as efficiently as possible.

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Sure, Apple can try to 'simulate' that there are four cores - but that simply won't work for all apps.

Thanks for expanding on your position but I am going to have to disagree with it. Grand Central Dispatch will handle those issues. Apple will tell the developers to use it and that will be that. Why would they not want to? It will be in their best interests to do so.. I'm not saying there wont be some grumbling from those who are hitting the hardware cores directly for greatest speed but those techniques will be deprecated. The software developers will fall in line.
We shall find out soon enough so no point in arguing past this point. Apple makes the final decisions not us.