Become a MacRumors Supporter for $25/year with no ads, private forums, and more!

MacRumors

macrumors bot
Original poster
Apr 12, 2001
56,518
19,271



At its media event introducing the new iPhones earlier this month, Apple highlighted several chip innovations included on the iPhone 5s including a new A7 main chip with one billion transistors and a smaller M7 "motion coprocessor" designed to efficiently measure accelerometer, gyroscope, and compass data and thus allow for enhanced fitness tracking, navigation, and more.

Chipworks and iFixit have now posted a teardown revealing what's inside these chips, as well as several other components of the iPhone 5s, offering an interesting first glimpse at these components at the heart of the device.

In looking at the A7, Chipworks noted that it is indeed manufactured by Samsung using its 28-nm process node. Apple has been seeking to shift its A-series chip production from Samsung to TSMC, but TSMC's chip production will reportedly not start until early 2014.

Gate pitch comparison of A7 and A6 (click for larger)
For the A7, Apple and Samsung have reduced spacing between transistors to 114 nanometers, a 7.3% decrease compared to the A6 chip. That denser transistor packing plus a slightly increased die size has helped Apple to fit approximately one billion transistors on the chip.
It turns out that the A7?s "gate pitch" -- the distance between each transistor -- is 114 nm, compared to the A6?s 123 nm.

Those 9 nm are a big deal. Looking to improve on their current 32 nm process, Apple decided to make the A7 with the same 28 nm process as the eight-core Samsung Exynos 5410, the current flagship CPU for Samsung's own Galaxy line.
A7 transistor die photo (click for larger)
Chipworks also took a look at the M7, which is actually an ARM Cortex-M3 part from NXP running at 180 MHz. The chip allows for low-power collection of motion data drawn from a Bosch Sensortec accelerometer, an STMicroelectronics gyroscope, and an AKM magnetometer.
After collecting information from the accelerometer, gyroscope, and magnetometer, the M7 performs some matrix math processing magic to produce an absolute orientation of the phone relative to the world. This data is then passed to the A7 in a neat package, probably in the form of three headings (roll, pitch, and yaw).

Using the A7 to monitor this sort of data would be mega-overkill, so the M7 was introduced to maintain a constant, low-power watch over these sensors.
M7 die photo (click for larger)
Finally, Chipworks performed some analysis on several other components from the iPhone 5S, including the rear camera sensor and LTE modem, while iFixit pointed to the Wi-Fi module and various radio and power amplifier components that all work together to provide connectivity for the new iPhone.

Article Link: Inside Apple's A7 Chip, M7 Motion Coprocessor, and More from the iPhone 5s
 

chrmjenkins

macrumors 603
Oct 29, 2007
5,322
154
CA
There is a very large block of SRAM/cache above the GPU (looks around 4MB) that contributes positively to the density. That contributes 192 million transistors on its own. Add the 1MB of L2 from the CPU and you're at 240 million, almost a quarter of the total transistor count.

edit: Here's anandtech's annotated image. The CPU cores are outlined in yellow. The four GPU clusters and supporting blocks are in blue.

A7-annotated.jpg


http://www.anandtech.com/show/7355/chipworks-provides-first-apple-a7-die-shot
 
Last edited:

SmoMo

macrumors regular
Aug 20, 2011
210
16
Integrating

Still haven't figured out what the M7 actually does...

I'm not 100% sure but I would guess it is probably applying a Kalman filter : http://en.wikipedia.org/wiki/Kalman_filter

When you have several overlapping sensor inputs you can combine them in such a way to minimise potential error.

In the case of the iPhone, the Compass heading can be used to calibrate heading and the accelerometer/gyroscope used to integrate minute changes that the compass is not sensitive enough to pickup.

The ultimate goal would be to also integrate GPS coordinates, and have a system accurate enough that it could track your movement ( by integrating accelerations twice ) but as I understand it the accuracy of the sensors is still way too low for this to be feasible.
 

Virtualball

macrumors 6502
Jun 5, 2006
399
8
For those who have the 5s, does rotating the device happen faster than on previous devices? Since the M7 constantly polls the location and updates the A7 when asked, it would be understandable if the switch to landscape is near-instantaneous because the information is already ready for the CPU without having to poll the devices itself.
 

Bhatu

macrumors regular
Apr 1, 2013
169
86
OMG! I was under impression that aliens were doing the magic inside A7 and M7! :D

8069625_f260.jpg
 

Mark Booth

macrumors 68000
Jan 16, 2008
1,642
482
Since the M7 co-processor will surely end up in future iOS devices, NXPI might not be a bad stock to pick. We'll see! :)

Mark
 

Gav2k

macrumors G3
Jul 24, 2009
9,216
1,607
Still haven't figured out what the M7 actually does...

Ok simple terms..

In the ip4,4s and 5 the processor deals with everything the sensors in the phone feed back and although the processor does it's best to sit in a low powered state it still processes the information so when requested it's there and available.

On the 5s the m7 chip which is running just fast enough to process the information in the background sipping battery life. So this allows the a7 to idle in a better state and when the information is required it can pull it straight from the m7 without polling the 3 separate sensors.

The battery saving potential of this is massive.
 

richard371

macrumors 68040
Feb 1, 2008
3,162
1,330
Many of the 5S are having issue where the accelerometer or gyro are off 4 or more degrees. The 5 and 4s were far more accurate.
 

Paradoxally

macrumors 68000
Feb 4, 2011
1,758
2,265
Ok simple terms..

In the ip4,4s and 5 the processor deals with everything the sensors in the phone feed back and although the processor does it's best to sit in a low powered state it still processes the information so when requested it's there and available.

On the 5s the m7 chip which is running just fast enough to process the information in the background sipping battery life. So this allows the a7 to idle in a better state and when the information is required it can pull it straight from the m7 without polling the 3 separate sensors.

The battery saving potential of this is massive.

Yes, the M7 is only for motion tracking activities (not for general data processing). So if you're walking, it doesn't need to wake up the A7 chip as the M7 controls the accelerometer.
 

840quadra

Moderator
Staff member
Feb 1, 2005
8,900
5,180
Twin Cities Minnesota
Ok simple terms..

In the ip4,4s and 5 the processor deals with everything the sensors in the phone feed back and although the processor does it's best to sit in a low powered state it still processes the information so when requested it's there and available.

On the 5s the m7 chip which is running just fast enough to process the information in the background sipping battery life. So this allows the a7 to idle in a better state and when the information is required it can pull it straight from the m7 without polling the 3 separate sensors.

The battery saving potential of this is massive.

That and I think it will have much more use in the future with iBeacons. No need to fire up the A7 when the M7 can process in Bluetooth Wireless location information of nearby BT iBeacons.
 

polterbyte

macrumors 6502
Sep 24, 2012
344
518
Brazil
I wonder if some descendant of the A7 will be able to replace intel inside a future MacBook. Apple seems to be building up the power inside its microprocessors for something along those lines.
 

carfac

macrumors 65816
Feb 18, 2006
1,235
29
Many of the 5S are having issue where the accelerometer or gyro are off 4 or more degrees. The 5 and 4s were far more accurate.

Have not noticed this. Mine (slate) seems OK, but I will start watching it closer.

Is it just yours, or is there a pattern? What color?
 

JHankwitz

macrumors 68000
Oct 31, 2005
1,911
58
Wisconsin
Chip Technology

This chip technology is mind boggeling and truely amazing. I remember building my first computer (if you can still consider it that) using a few dozen vaccum tubes back in the late '50s. Each of the tubes contained up to 4 electronic switches. That baby was hot... literally. Now this little chips contains a billion switches and just warm to the touch... truely amazing!
 

cababah

macrumors 68000
Jun 11, 2009
1,873
446
SF Bay Area, CA
Best way I have heard it explained: The A7 is the chip of tomorrow; not today.

All of the side-by-side comparison tests show no significant real world performance benefit to the A6 in the iPhone 5 (basic OS use, no gaming). By the time the 64-bit architecture catches on and is fully realized by developers, the iPhone 6 will be looming around the corner...
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.