The iPhone 5 Review
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on October 16, 2012 11:33 AM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone 5
Apple's Swift: Visualized
Section by Anand Shimpi
Based on my findings on the previous pages, as well as some additional off-the-record data, this is what I believe Swift looks like at a high level:
Note that most of those blocks are just place holders as I don't know how they've changed from Cortex A9 to Swift, but the general design of the machine is likely what you see above. Swift moves from a 2-wide to a 3-wide machine at the front end. It remains a relatively small out-of-order core, but increases the number of execution ports from 3 in Cortex A9 to 5. Note the dedicated load/store port, which would help explain the tremendous gains in high bandwidth FP performance.
I asked Qualcomm for some additional details on Krait unfortunately they are being quite tight lipped about their architecture. Krait is somewhat similar to Swift in that it has a 3-wide front end, however it only has 4 ports to its 7 execution units. Qualcomm wouldn't give me specifics on what those 7 units were or how they were shared by those 4 ports. It's a shame that Intel will tell me just how big Haswell's integer and FP register files are 9 months before launch, but its competitors in the mobile SoC space are worried about sharing high level details of architectures that have been shipping for half a year.
Apple's Swift core is a wider machine than the Cortex A9, and seemingly on-par with Qualcomm's Krait. How does ARM's Cortex A15 compare? While the front end remans 3-wide, ARM claims a doubling of fetch bandwidth compared to Cortex A9. The A15 is also able to execute more types of instructions out of order, although admittedly we don't know Swift's capabilities in this regard. There's also a loop cache at the front end, something that both AMD and Intel have in their modern architectures (again, it's unclear whether or not Swift features something similar). ARM moves to three dedicated issue pools feeding 8 independent pipelines on the execution side. There are dedicated load and store pipelines, two integer ALU pipes, two FP/NEON pipes, one pipe for branches and one for all multiplies/divides. The Cortex A15 is simply a beast, and it should be more power hungry as a result. It remains to be seen how the first Cortex A15 based smartphone SoCs will compare to Swift/Krait in terms of power. ARM's big.LITTLE configuration was clearly designed to help mitigate the issues that the Cortex A15 architecture could pose from a power consumption standpoint. I suspect we haven't seen the end of NVIDIA's companion core either.
At a high level, it would appear that ARM's Cortex A15 is still a bigger machine than Swift. Swift instead feels like Apple's answer to Krait. The release cadence Apple is on right now almost guarantees that it will be a CPU generation behind in the first half of next year if everyone moves to Cortex A15 based designs.
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Spunjji - Friday, October 19, 2012 - link
Incorrect. See HP Elitebook, Sony Vaio S15, Asus Zenbook, etc... that does depend on your definition of "trackpad that doesn't suck", but personally I'd take an Elitebook with actual buttons over the Apple effort any day, so that bit really is swings and roundabouts.doobydoo - Friday, October 19, 2012 - link
'so that bit really is swings and roundabouts'That's like saying a Ferrari is overpriced because you prefer cup holders so therefore you get more car for less when you buy a Skoda.
Also, you have to consider size, weight, battery life and performance.
You can't find a single laptop which matches the air on all of the above.
Sufo - Tuesday, October 16, 2012 - link
You're right to an extent, however it's worth mentioning that it's a lot easier to find unlocked non-apple phones at good prices on auction sites etc. It's very hard to get much less than list price on iphones, even several months after release.As for Macs, it depends entirely on which country you buy them in - in the UK for example, it is cheaper to buy a plane ticket to the States and buy a 15" w/ retina there than it is to buy one locally - the same could not be said for similarly specced PCs.
Spunjji - Friday, October 19, 2012 - link
Truth. Unfortunately Apple prices are subject to the perception that Apple products hold their value better, which in a purely practical sense really isn't any more true than for any other product. But the market does as the market does. :)Spunjji - Friday, October 19, 2012 - link
People who defend Apple's prices with fake numbers just want to whine about people who don't like Apple... see how easy that argument is to return? Please.A5 - Tuesday, October 16, 2012 - link
I'd say the smartphone market does a fairly good job of dropping prices on products that need it.The only product I can really think of that is an outstanding "value" proposition would be the $350 unlocked GNex combined with a prepaid plan. The current high-end devices (One X, GS3, iP5) all seem to be fairly priced relative to each other.
steven75 - Wednesday, October 17, 2012 - link
When I was looking at what I should price my 2.5 year old iPhone 4 at, I found the GS3 is already down to iPhone 4S prices on the resale market.Android phones just don't hold resale value vs iPhones, even the flagships, it's Mac vs PC all over again in that area. ;)
pseudonymmster - Tuesday, October 16, 2012 - link
"A processor license gives you the right to taken an ARM designed CPU core..."I think "taken" should've been "take" :D
karasaj - Tuesday, October 16, 2012 - link
Nice review guys... all I have to say :Pjjj - Tuesday, October 16, 2012 - link
On the scuffing, would you buy a car that rusts if you drive in the rain? This is clearly a design flaw, a sane company would recall the product and use a more apropriate material.You shouldn't be telling people to deal with it (except the ones that are happy to own the first colour changing phone).The size of the SoC in phones matters less and less as we go forward,more integration,more specialized cores,just because it's there it doesn't mean that much of the area is powered at the same time and the cost of silicon is less of a problem too.The limitation is power and /heat not area.
" if everyone moves to Cortex A15 based designs." - everybody ,in the high end, moves to quad Krait since A15 is likely to be just dual core for a while.
Nice review overall but,as always, your battery of benchmarks is misleading and no storage perf,really hoped for more to better understand this new core.