Apple A7 is now 64-bit

[bullzz]

this is unbelievable. 1 major step towards integrating mac os with ios

 

[sefsefsefsef]

64-bit's main advantage is being able to conveniently address more than 4GB worth of data. We are not yet to the point that this is an issue in smartphones. Other than that, what does 64-bit give us?

 

[bullzz]

well even if its 64 bit, the os is going to do basic phone functionality. imagine docking ur phone and start using it as a PC

 

[Fjodor2001]

ARM v8 based?

 

[Nothingness]

ARM v8 based?

Yes.

 

[jhu]

Or they're on their way to ditching Intel entirely. Apple has an ARM architectural license so they could conceivably design their own high performance ARM chip and put them in MacBooks.

 

[Exophase]

Managing even 2GB of physical memory becomes cumbersome in a 32-bit kernel, and you're already looking at major compromises with 4GB. So the problems start before you hit > 4GB. Android phones and tablets have been at 2GB for a good year now. Do you really think it's best to only move to 64-bit right as you need it?

I can easily see why Apple wanted to avoid the whole headache of having more physical memory than they have virtual address space to manage. Most likely the majority of user space apps will stay 32-bit for quite a while, but will have access to a little more virtual address space breathing room which lets them take up allocate more memory and reduces fragmentation. Some will move to 64-bit if it brings a minor performance benefit due to the new architecture or if they have an exotic application (sometimes user apps can benefit from huge virtual address allocations that grossly exceed the amount of free memory - this can be useful for emulation for instance, AFAIK Dolphin does stuff like this)

 

[bullzz]

@jhu - yes, i knew this is inevitable but was thinking it was still 2 yrs away!!

 

[Broheim]

64-bit's main advantage is being able to conveniently address more than 4GB worth of data. We are not yet to the point that this is an issue in smartphones. Other than that, what does 64-bit give us?

it's more of a nipping it in the bud thing, better to make the switch early than at the very last minute when you know it's coming.

 

[Subyman]

Not impressed at all.

Seriously, I am watching the live blog on this. I really DONT need my phone to be a super computer.

Since having more than 4GB of RAM makes a device a super computer...

Maybe you forget, the iPad uses iOS as well. With the new productivity apps that Apple is bundling in for free, I can definitely see a need for more than 4GB eventually. Better to smooth the transition over a few years than develop 64bit "when its needed."

 

[Face2Face]

Why is a 64bit SOC needed in a phone now? Is this new CPU still a dual-core? How much memory?

 

[Maximilian]

Thread reminds me of 2003, A64 all over again.

"Who needs more than 4GB of ram pfft gtfo!"

Better to have and not need than need and not have. :thumbsup:

I feel old

 

[ShintaiDK]

It was obvious for along time that 32bit ARM was an issue. Just look at Samsung and 3GB devices. They even had to develop "special" memory for it.

 

[Exophase]

I guess no one really takes me seriously when I say that 64-bit doesn't just become helpful when you have > 4GB of RAM :/

Why is a 64bit SOC needed in a phone now? Is this new CPU still a dual-core? How much memory?

I think iPhone 5S is going to be quad core or possible triple core, because they claim up to 2x CPU performance over iPhone 5, and it's hard to believe they achieve that with the same core count. Maybe if they've implemented some kind of turbo and can clock one core a lot higher, or if they've all around relaxed their power budget a lot.

It was obvious for along time that 32bit ARM was an issue. Just look at Samsung and 3GB devices. They even had to develop "special" memory for it.

You talk as if no one uses RAM quantities that aren't powers of 2. 6GB laptops are common. I'm sure 3GB modules cost less to make than 4GB ones, and could still be really pushing the limits for what they can stack in a PoP.

 

[Nothingness]

I guess no one really takes me seriously when I say that 64-bit doesn't just become helpful when you have > 4GB of RAM :/

Because even here more than 90% of the people aren't devs.

I think iPhone 5S is going to be quad core or possible triple core, because they claim up to 2x CPU performance over iPhone 5, and it's hard to believe they achieve that with the same core count. Maybe if they've implemented some kind of turbo and can clock one core a lot higher, or if they've all around relaxed their power budget a lot.

I think we can rule out 4 cores, or they'd have said "more than 2x" not "up to 2x" (unless they also reduced clock frequency).

 

[ShintaiDK]

You talk as if no one uses RAM quantities that aren't powers of 2. 6GB laptops are common. I'm sure 3GB modules cost less to make than 4GB ones, and could still be really pushing the limits for what they can stack in a PoP.

http://www.samsung.com/global/business/semiconductor/news-events/press-releases/detail?newsId=12979

Yes, special memory just for the 32bit ARM limit.

 

[sm625]

64 bit is so bloated compared to 32. The last thing we need are 64 bit phone apps that consume twice as much storage space for no tangible benefit. I wonder if this is sponsored by AT&T and Verizon... as they are the only ones who will benefit from a move to 64 bit.

 

[TerryMathews]

My guess would be that this is more to expand the addressable memory space than anything else.

I honestly don't know, does the iPhone have any form of XIP?

 

[insertcarehere]

considering this is still a dual core, >1 billion transistors is a lot for a phone SoC, the CPU cores probably have been seriously overhauled besides adapting Armv8.

 

[joshhedge]

considering this is still a dual core, >1 billion transistors is a lot for a phone SoC, the CPU cores probably have been seriously overhauled besides adapting Armv8.

We don't know the core count yet. It's all still speculation.

 

[Schmide]

64 bit is so bloated compared to 32. The last thing we need are 64 bit phone apps that consume twice as much storage space for no tangible benefit. I wonder if this is sponsored by AT&T and Verizon... as they are the only ones who will benefit from a move to 64 bit.

Arrrgggg. Dude the processor runs in two modes, AArch64 and AArch32, the same way modern x86-64. Most code will still be 32bit based and programmers and users should see no difference in their app model. However, the OS now has new memory pool and flat addressing of video memory, it no longer has to solely exist in the 32 bit space as well.

 

[Exophase]

Because even here more than 90% of the people aren't devs.

Well, I don't expect them to know it already, or necessarily understand why, but it'd be nice if they listened and maybe asked instead of just ignoring it ;p

Maybe if I just linked to Linus Torvalds ranting about it they'd take it on authority.

I think we can rule out 4 cores, or they'd have said "more than 2x" not "up to 2x" (unless they also reduced clock frequency).

"Up to 2x" CPU performance is actually exactly what they said about the A5 chip, which both doubled the core count and moved from Cortex-A8 to A9, while keeping the clock speed the same. So there's a pretty direct precedent for doing it again, although it'd be a little disappointing if it's just quad core. Triple core would be kind of interesting, seems like a reasonable tradeoff.

http://www.samsung.com/global/business/semiconductor/news-events/press-releases/detail?newsId=12979

Yes, special memory just for the 32bit ARM limit.

Nowhere in that press release does Samsung say they made 3GB instead of 4GB memory because of address space limitations. I already said it in my post, it's not special just because it's 3GB. We don't know what the practical considerations are for a 3GB module vs a 4GB one.

64 bit is so bloated compared to 32. The last thing we need are 64 bit phone apps that consume twice as much storage space for no tangible benefit. I wonder if this is sponsored by AT&T and Verizon... as they are the only ones who will benefit from a move to 64 bit.

A 64-bit app isn't going to need twice as much storage - by storage I assume you mean where your apps go, like flash. There's no reason why it should need any more storage at all, except that the instructions are less dense than the Thumb-2 ones currently available in 32-bit ARM (I have no idea if this is something iOS apps use or not. Android ones generally do). But that has nothing to do with it being 64-bit.

If you were referring to RAM, there is generally a penalty in RAM footprint from moving to 64-bit because your pointers are twice as large. But typically it's nowhere close to 2x, even if you don't employ any kind of pointer compression. A lot of data is raw or flat as opposed to containing complex data structures with a lot of pointers.

It could trend worse on non-NDK Android apps though, historically it's been a challenge with Java and that would translate to Dalvik. There are still some ways to deal with it.

One thing I'm not sure everyone realizes that going 64-bit doesn't maen they're dropping 32-bit support nor does it mean everyone is going to start making 64-bit apps. A few heavy duty ones will be, but I suspect most people will opt to stay with 32-bit for a while. 64-bit is of the most benefit to the OS kernel.

I honestly don't know, does the iPhone have any form of XIP?

Are you from a GBA homebrew community or something? XIP doesn't work with NAND flash, which is what most devices use for storage.

 

[Nothingness]

I'm surprised no one noticed this: >1B transistors for 102mm². That's denser than 22nm Ivy Bridge with it 1.4B transistors and 160mm².

 

[SammichPG]

64 bit ARM leaves me with conflicting feelings, it's quite possible that this will be the isa that the majority of consumers will use in the future.

On one hand more companies battling in the market is a positive thing compared to the x86 duopoly, but I can't see us consumers ever getting the same freedom we enjoy regarding OS upgrades in the PC market.

People are spending an increasing amount of money into devices with strong planned obsolescence "features" (locked bootloader, locked os, locked app platform) and this is not good.

This whole mobile race looks similar to the 80s pc market in many ways.

 

[Exophase]

I'm surprised no one noticed this: >1B transistors for 102mm². That's denser than 22nm Ivy Bridge with it 1.4B transistors and 160mm².

So it's a pretty safe bet this is TSMC 28nm right? I don't think Apple has ever reported transistor counts before, it sounds like they want to show it off. A good indication that the density is substantially better than it was with Samsung, which is something I've always strongly suspected.

For a comparison, XBox One's SoC is 363mm^2 and about 5 billion transistors, making it even denser than A7 (it's also on TSMC 28nm). But a lot of it is SRAM.