The processor in the system-on-chip Apple A8 have 2-core, its clock frequency is almost not increased – nevertheless, in most tests he defeated the opponents with which a large number of cores overclocked up to large clocks.

The Apple A8 was announced on 9 September 2014 in an absolutely epic location: Cupertino, flint center, the Bolshoi theatre of De Anza College. It was there in January 1984 was declared the first Mac in the spring of 1998 – the first iMac. The Apple A8 performance was not the main theme of the event – it was a tiny episode in a different presentation, too, is not the most important that day. About the event and its topics another time.

Phil Schiller announced the new system-on-chip the absolute minimum of information. That chip has 2 billion transistors (in the chip in General, how many of them in the processor remains a mystery) that the Apple A8 is 13% smaller than its ancestor, and that is the new chip technology of 20 nm.

Already surprising: Apple A7 made by Samsung, the technology of 28 nm, 20 nm is jump over a step. Is “relationship” an Apple with the Taiwanese company TSMC has gone so far?

Phil would not be a top expert in marketing (selected from hundreds of applicants by Steve jobs), if not announced winning moments of new items (don’t sell the steak, and the sizzle and aroma). Compared to Apple A7, CPU performance increased by 25% (compared with the first iPhone in 50 times). The performance of the GPU by 50% (compared to the first iPhone – 84 times). And efficiency increased by 50%.

Applause, and Phil moved on to other aspects is not the most important topic. I almost forgot: he mentioned and Apple M8 motion coprocessor, which added digital barometer, allowing to determine (with high accuracy) height of its position above sea level. Your and your biological owner.

Official information about the new system-on-chip was limited to this information. This is an outrage? Something like, Yes – here are hundreds (if not thousands) of inhabitants of our planet to get with what incomparable pleasure from exposing hidden from them by Apple. On a scale of “shoot-to forgive is to reward” I’d appreciate it a crime Apple intermediate rating between the second and thirdcontinuation of the series Pro processors from Apple.

Revealing the secrets of the “Apple” of the stone

Chipworks, iFixit, and others, having obtained their hands on a mysterious artifact, began his autopsy. A well-informed public is eagerly waiting for the results. It went and other methods of operative-investigative work.

To enter would be for the fire wall, and make the harsh interrogation of captured “languages” – but the Republic of California it is not accepted.

The chip was produced by TSMC. The processor was smaller (12,2 sq mm instead of 17.1 sq. mm) than the Apple A7, and very like him. While in the “plist”files, iOS 8 was not found now the processor name, it was called “Enhanced Cyclone”.

Apple has been practicing in the development of processors, the method tick-tack? And why not?

The most dangerous rival Apple’s processors, 64-bit ARM Cortex-A57, is still preparing to debut. And, judging by its performance characteristics, “improved Cyclone”, he is not threatened, they were about equal.

Here is a picture of the Apple A8, taken with an electron microscope for a couple of million dollars company Chipwork (Apple A8 before it was cut thin top layer):

Like the decent size of the settlement from space. Clouds, houses, streets. Chipworks has spent a lot of time and effort to decrypt it all, figured out some of the most important components of the system-on-chip, and caused them to “space the”. A large part of the mystery remained a mystery.

The processor turned out to be 2-core, GPU – 4-core. Its internal name was Typhoon, it really has been improved and redesigned version of the Cyclone. Its clock frequency, the devices announced with it (you’ll never guess what it was), was 1.4 GHz, 0.1 GHz more than the Cyclone. Structurally (the number and size of pipelines, cache sizes of all three levels and other details) Typhoon was even closer to the Cyclone than it seemed at first glance. 1 GB LPDDR3 (1 333 MHz).

That is, against a 4-core competitors with clock frequencies around 2 GHz he didn’t have the slightest chance? Was not. But the facts contradict this logical conclusion so that made to think about the law of logic to exist. In races with them, the Apple A8, as a rule, was in the lead. And even the Apple A7, now obsolete, too, gave unexpectedly good results. The iPhone 5s was third, yielding only two new iPhone which I’m not going to say anything.

The experts came to different conclusions, the reasons for the calling of a violation of the laws of physics, logic, and other Sciences turned out long and carefully. Raw and real performance is a different performance, from which the value has only the second.

If you control all the critical elements of the device: CPU, operating system, and the design of the device, and optimize their interactions, manic and hard, it is possible. Magic becomes reality. Great job, Apple!

A little more

Compared to Cyclone, Typhoon seriously changed blocks only integer calculations, and a computation of floating point numbers. To perform the same operations Typhoon was required less CPU cycles than the Cyclone. In addition, the increase in throughput of all interfaces between the blocks of the system-on-chip, too, was drawn the most attention – and these abilities have intensified in and of themselves, due to smaller lithography.

As in the Apple A7, Apple A8 three levels of caches. First – in each core, the same 128 KB (64 KB is the instruction cache and 64 kilobytes of the data cache). The second total for the entire processor, of size 1 Megabyte. The third one is General for the entire system-on-chip, its size is 4 Megabytes. Everything is the same as in the Apple A7, but access to them is faster.

The same ARMv8 AArch64 architecture, 32/64 bit. Design sharpened to achieve very high performance at relatively low clock frequencies. From the standpoint of the unintelligent layman 1.4 GHz and 2 cores is not cool. Does not sound. In fact, this is exactly what I wanted to achieve all the manufacturers of mobile devices.

Just in case, here’s an enlarged photo of the processor. Maybe you’ll see it’s something that I missed?

The “out of space”. District Typhoon:

Companions Typhoon

Outside of the system-on-chip is constantly waking tiny chip Apple’s M8, the development and production of transnational corporations NXP Semiconductors, the headquarters of which are located in the Netherlands, in Eindhoven.

The designation of this chip LPC18B1 (Apple M7 was LPC18A1), it’s controller based on the ARM Cortex-M3. The technology which produced this chip is unknown. In the price-sheets of the NXP Semiconductors no information about it. The coprocessor was manufactured exclusively for Apple, and was developed by engineers of both companies together.

About the barometer, was added to the gyroscope, compass and accelerometer, I have already mentioned. But was in the Apple M8 other features: CMMotionActivity class from the framework Core Motion has another constant value for “type of movement”: movement on the bike. Apple M8 now recognize him.

Apple M8 worked with sensors, processing and storing data received from them, at any time, even when the device was in an inactive state. System-on-chip had not “Wake up” to respond to receipt of data from sensors, and it is couple of orders of magnitude more voracious than the tiny Apple M8. But this chip was not one of these sensors.

The GPU in the Apple A8, PowerVR GX6450, the company Imagination Technologies, the architecture of Rogue (i.e., “crook”, “crook”, “crook”), generation Series6XT. The descendant and heir of PowerVR G6430, Apple A7 (who was also a Rogue, a bunch of crooks and swindlers).

PowerVR GX6450, like PowerVR G6430 – processor 4-core. Or 4-clustered, as they were called producers. The reasons they have for this was, but the designation did not stick.

After the presentation, Apple’s A8, the expert community rightly assumed that it uses a 6-core PowerVR as 20 nm and 50% increase in graphics performance. Apple on such matters is not responding. But the autopsy found 4-core GPU, they could only be GX6450 PowerVR, Imagination Technologies confirmed this assumption.

Could the Typhoon together with a PowerVR GX6450 to cope with millions of pixels on screens of the two new iPhone? Could, because I could. And because the ancestor of this GPU, PowerVR G6430, much less productive, successfully coped with millions of pixels the iPad Air.

It’s time to talk about the “two new iPhones”?

To be continued