Apple's A7 Processor Truly 'Desktop Class', iOS Apps Don't Take Full Advantage

[Atlantico]

Sure, lets make ridiculous comparisons to justify prejudiced opinions. Because that's logical and fun...NOT.

Those are *desktop class* CPUs.

 

[Kariya]

Those are *desktop class* CPUs.

...and you're comparing them to a *SoC*

 

[chrmjenkins]

I'm going to get blasted for this because its a criticism but here it goes.

A7 is a very wide core which is why it has a high theoretical performance. It therefore has a lot of power that is untapped.

However, extracting that power massively increases power consumption.

We can look at anand's power test to see this.

http://images.anandtech.com/reviews/tablets/apple/ipadair/krakenpowersm.png

Image

Easily see that under heavy load the A7 power use (there is no GPU running) is more than twice that of the a6X at around 7-8W. Under lighter loads (the massively wide core is not utilized) power drops down to ~ 3W. So while its possible to extract performance you cannot do that without increasing power consumption. If you add the GPU (at least ~3W under heavy load) you are looking at 10-11W power draw.

For comparison the A7 is using clock for clock way more power than Haswell (Incidentally they are also a very similar size-the A7 dual core uses the same die space as a quad core A15 cluster). ULV Haswell will run prime 95 at 2.6 Ghz and that is 2 cores + HT in a 15W envelope. (Not counting the igp which will cause the chip to throttle but I'm not looking at the gpu in the A7). That is of course under full load, under light load.

Image

11 hours on a 54W battery

Ipad Air gets 10 hours on a similar test with a 32.4W battery

There isn't a whole lot going for the A7 (due to platform power consumption). Sure the ipad has better efficiency but (smaller high PPI ipad screen probably consumes the same amount of power as a 13" MBA screen) its rocking less RAM, much lower power storage (not a full SSD), and doesn't have to do with a lot of the I/O that Haswell has.

Don't get me wrong the fact that you can even compare Apple and Intel is impressive but there are quite a few caveats.

The other thing to note is that as Apple designs the CPU and software for the browser benchmarks and thus is able to get crazy optimization levels out of it. Look at Mantle performance gains (up to 100% in some cases). Just look at the efficiency Apple can get out of battery life on its macbooks.

This isn't just Apple. All SoC manufacturers have been pushing their max TDPs higher and higher to best one another. It will taper off soon enough and they'll be reliant on microachitecture and process improvements to gain headway.

 

[garylapointe]

This has been my experience too with the iPad Air and it happens with Chrome too, not just Safari. I usually have 3-5 tabs open and the reloading hasn't improved since the update to 7.1. I'm really thinking that Apple doesn't consider it a problem and that it the way it is designed to work at this point in time. It will be interesting to see what happens with the next iPad or iOS update. I'm betting on 2GB of RAM next time and maybe they will rework how memory is being managed.

Actually I've been paying attention the last few times I opened it. Safari might be a little better since 7.1, but I don't think it's caching as well as in iOS 6.

On the other hand, the darn app switcher stores hires screen captures of my apps for me (and they're usually out of date!!!), how much space does that waste?

Gary

 

[garylapointe]

And new (including some/most current) apps would definitely take advantage of that additional RAM, while at the same time in that one moment all older iOS devices would be rendered useless for anything current and new going forward, and significantly reduced in value on the second hand market (a market in which Apple products do exceptionally well, and one reason they continue to demand high prices when new).

Unfortunately, I think we're in for small increases in RAM, because Apple realises what would happen to all the older iOS devices. Both a sad thing and good thing (especially if you own older, even 1 generation older, devices).

They've updated the RAM before and it didn't cause that big of a problem, it certainly didn't make the devices "useless".

The original iPhone had 128MB, the 3GS had 256MB, the 4 had 512MB and then 1GB in the 5 (right?). The iPad went through similar growth starting with 256MB. Following their pattern (and manufacturing patterns), it'll likely double when the get around to upgrading it (unless they dedicate a portion to something else).

New graphic intensive programs that won't run on the current specs (that can't be done anyways) don't take away from an older machine (it can't run it anyways).

For many apps it'd just keep things running smoother and more efficient, right? Older iDevices would get those pauses and stutters that occasionally happen.

 

[gkarris]

I have the latest 15" MacBook Pro and that thing stutters when using multiple layers and luminosity masks in PS on the D800 files. These processors are way off being any use for PS.

Sorry, meant PS Mobile that is currently available for the iPhone/iPad - good enough for casual editing of jpegs...

 

[Atlantico]

...and you're comparing them to a *SoC*

Because they're being compared to *desktop class CPUs*

 

[Kariya]

Because they're being compared to *desktop class CPUs*

No they're not. Their architectures are. And fact is there are indeed similarities to existing desktop architecture.

Look, I'm bored of this dance. Therefore this will be my last response to you. Feel free to think/believe/compare what/how you want. It doesn't change the facts either way. But whatever makes you feel better...go for it.

I'm out.

 

[Atlantico]

No they're not. Their architectures are. And fact is there are indeed similarities to existing desktop architecture.

Look, I'm bored of this dance. Therefore this will be my last response to you. Feel free to think/believe/compare what/how you want. It doesn't change the facts either way. But whatever makes you feel better...go for it.

I'm out.

The architecture? Wow. <SNIP>. The ultra low power i7 isn't even compared to a desktop class CPU, even though it is legitimately similar in architecture to its desktop "equivalent".

The A7 is not comparable in any way shape or form to a desktop class CPU. <SNIP>

 

[Buddygor]

I think its hilarious that even Apple's old dual core A6 processor in the iPhone 5C from last year's model is on par with current top of the line" hexacore" Android phones like Galaxy S5.

The 64 bit A7 is in a whole 'nother league. Just goes to show how much more advanced iOS and their engineering team is combined with Apple's philosophy of precisely matching software with hardware. My guess is they have big plans for iOS and the A8 chip. Much bigger than just a phone.

Because unlike all other smartphone manufacturers, Apple isn't waiting for Qualcomm or some other chip maker to come out with something faster. If they want it, they'll make it.

 

[fertilized-egg]

Because unlike all other smartphone manufacturers, Apple isn't waiting for Qualcomm or some other chip maker to come out with something faster. If they want it, they'll make it.

I am still a bit puzzled by why Apple moved forward so aggressively with Cyclone. Qualcomm is still using Krait which was released earlier than Swift and it holds up pretty well. It's more interesting because of all the ARM-related rumblings on the laptop front and the talk of new product categories. Or maybe we're reading too much into it.

The architecture? Wow. <SNIP>. The ultra low power i7 isn't even compared to a desktop class CPU, even though it is legitimately similar in architecture to its desktop "equivalent".

The A7 is not comparable in any way shape or form to a desktop class CPU. <SNIP>

I see the mod has removed your other posting and my response to that but my earlier question still stands: did you read the article before commenting on it?

 

[Buddygor]

I am still a bit puzzled by why Apple moved forward so aggressively with Cyclone. Qualcomm is still using Krait which was released earlier than Swift and it holds up pretty well. It's more interesting because of all the ARM-related rumblings on the laptop front and the talk of new product categories. Or maybe we're reading too much into it.



I see the mod has removed your other posting and my response to that but my earlier question still stands: did you read the article before commenting on it?

I don't know. Even though they denied it, it seems that a merger of some sort between OS X and iOS is inevitable. Maybe a more advanced iOS-powered MacBook Air type computer? Otherwise, why put all your R&D into a desktop-class architecture?

 

[Atlantico]

I see the mod has removed your other posting and my response to that but my earlier question still stands: did you read the article before commenting on it?

Desktop class means only one thing, if you have to define it as something else then go right ahead.

But it still just means one thing and the A7 ain't it.



And yeah I read the article, did you?

"While AnandTech goes into great detail on the architecture of the A7 chip and how it compares to the A6, they conclude that the A7 chip is indeed -- as Apple claimed -- "desktop class" and "the rest of the players in the ultra mobile CPU space didn't aim high enough". "

 

[subsonix]

And yeah I read the article, did you?

"While AnandTech goes into great detail on the architecture of the A7 chip and how it compares to the A6, they conclude that the A7 chip is indeed -- as Apple claimed -- "desktop class" and "the rest of the players in the ultra mobile CPU space didn't aim high enough". "

What that means is that they agree with the apple claim.

 

[driftless]

I would have doubted this even a year ago, but for MacBook Air and Mac mini, I think it could happen with A8. Wonder if they could manage a 20+ hour battery life MacBook Air Retina w/ A8, 12" screen, reeeaaally thin, maybe 8GB RAM, 256 and 512GB solid state storage options. That would be an exceptionally tempting machine!

I have been keeping my eye on the rumors for this machine as well. I think that it would be killer, particularly in the max configuration. It seems that many of the posters in the several threads about a possible ARM rMBA are assuming x86 emulation. However, Apple may not include x86 emulation if they have iWorks, Aperture, and some of the major apps running from day one. It would be a game changer. If it is not x86 functional, I wonder if a touchscreen makes sense. It would be an interesting hybrid that would appeal to many, IMHO. I would still use my desktop machine but it would be a fun, and fully productive, device.