Tablet processor - let's talk about Bay Trail

Slowly comes to an end in 2013; The new, 2014, Intel is preparing to meet the new generation of processors (more precisely, SoC) Atom for mobile devices and PCs, codenamed Bay Trail. In this post, we will compare the new chips with the previous generation and see how much they have advanced. Of course, we are most interested in consumer characteristics - how much better and more fun will we live with the Bay Trail?

The Bay Trail processor family consists of three groups. The processors with the letter N (N3000 - "Pentium" and N2000 - "Celeron") are designed for laptops, with the letter J (J2000 and J1000) - for desktop PCs. We are most interested in those with the letter Z - for tablets. There are also two series: Z3700 - quad-core for tablets under Windows and Android and dual-core Z3600 for Android tablets. All processors are made on 22nm tri-gate technology.

Consider what are the processors Intel Atom Z3000 series. Their main characteristics are:

• 4 cores / 4 threads, 2 MB L2 cache; out of order execution of instructions
• Intel Burst (we'll talk about it below);
• support for 64-bit OS;
• new to Atom SSE4.1 vector instructions;
• support for dual-channel memory LPDDR3-1067 (maximum 4 GB);
• Intel HD Graphics graphics core with the same architecture as Intel GPU in Core processors - 4 execution units (8 threads each);
• dynamic frequency of the graphics core, hardware acceleration of encoding / decoding;
• New technologies of virtualization and security.

The general architecture of the chip is shown in the figure below (clickable).


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For clarity, we will make a comparative table of the characteristics of the platform of the previous generation Clover Trail + (Atom Z2760) and Bay Trail. The most fundamental changes are circled in blue.



Traditionally for this year, we see especially many improvements in the graphic part. Moreover, it is now fundamentally the same for the Intel Core and Intel Atom. The graphic core separating the thermal power from the CPU has a turbo mode. DirectX11 and OpenGL ES 3.0 API are now available on tablets! High resolution displays are supported (up to 2560x1600).

H.264 HD hardware coding can now be performed with the highest quality profiles, while the power consumption remains low. MPEG2 hardware encoding is also partially accelerated. The list of hardware decoded media formats has been expanded: H.264, VC1, MPEG2, MVC, VP8, MPEG-4 / H.263, MJPEG.
Testing showed that 1080p24 @ 23Mbps hardware transcoding is performed with the same quality on the new Intel platform 3 times faster than on the iPhone 5!


Noise filtering - before and after filtering

The video output subsystem has a flexible dual configuration, which includes two digital DDI interfaces.



To save energy, the display uses Intel Display Power Saving Technology (Intel DPST) technology - lightening and improving the displayed image, which helps reduce the backlight brightness. The reduction in power consumption of the display as a result is 20-50%.



The combined Bay Trail memory controller can work with both DDR3L-RS and LPDDR3. Dual-channel memory is supported, aggressive energy saving algorithms are applied. Bay Trail's memory bandwidth is twice as high as Clover Trail!


Memory speed comparison. Here is (CLT +) = Clover Trail +, BYT = Bay Trail

The new camera module allows you to shoot video 1080p60, equipped with a digital stabilizer. The developers managed to achieve a minimum delay when taking photos. The module allows you to connect two cameras with matrices from 8 to 13 megapixels. Comparison with Clover Trail, obviously, in favor of the new generation

	Clover trail	Bay trail
Video shooting	1080p30	1080p60
Double video shooting	Not supported	Both 1080p30
Photo during video shooting	Not supported	High resolution photos
Digital stabilization	In two axes	Four axes (+ rotation)

A lot has been done to increase the energy efficiency of the platform. And one of the first places here is Intel Burst Technology 2.0 technology , which allows the cores to work faster than the standard operating frequency, if this does not violate the operational limitations on temperature, consumption, etc. Thus, one core can take a sporadic load from the other, reducing the overall power consumption. In the new version of Intel Burst, the load distribution can occur not only between the computational cores, but also the graphics, as well as the camera image processing subsystem and the display.
The animated diagram below shows the principle of operation of the technology:



Thinner process technology, optimization of the architecture and new technologies made it possible to achieve a 2-6.5 fold increase in processor performance (depending on the application), with a significant reduction in consumption. This means that in 2014 we will see powerful, long-playing mobile devices on the Intel platform - according to the developers' forecasts, it’s realistic to talk about 8-10 hours of video playback for the Bay Trail.

In preparing the post, IDF 2013 materials were used, the author is Shreekant (Ticky) Thakkar.