ARM chips: Understanding the differences between the Hummingbird, Snapdragon, OMAP and Tegra

Introduction

Unlike the x86 processors, which are produced by Intel and AMD (and also lower volume by VIA), the ARM chips are not produced by a single company, but licensed and produced by several manufacturers.

The ARM Ltd. , which is responsible for developing the chips and owns the rights to the architecture, produces processors, limited to licensing the designs at affordable prices for other manufacturers, who may opt for different license types, ranging mere license to produce the chips, the options that modify the chips, include additional components, or even have full access to the microcode and develop a compatible chip.

This is the case of manufacturers such as Qualcomm, Texas Instruments and Samsung, who develop their own solutions, including drivers and helpers often optimizations inside the processing core.

With the exception of two Tegra , which includes two ARM Cortex A9 unmodified, combined with the GPU developed by nVidia and other components, virtually all SoCs for high-end smartphones on the market that we include changes in the processing units that influence the performance and electrical consumption. While it is common to say that the Qualcomm Snapdragon processor includes a Cortex A8, from a technical standpoint this is not entirely correct, since it includes a processor developed by Qualcomm itself, the Scorpion, which despite being based on and compatible with Cortex A8 it includes many changes and a slightly different performance. Let us then to detail the peculiarities of each chip:

TI OMAP

Texas Instruments has taken the lead in the rise of super-phones with Android, equipping both the original when the Droid Droid Droid and X 2.Nevertheless, they ended up losing ground thereafter, watching the rise of the chips to Qualcomm and Samsung, which are now used in most new models.

Just like Qualcomm and Samsung, Texas has a license for the Cortex A8 architecture, which allows her to make changes in processor design, and group it with other ingredients as desired. Nevertheless, Texas does not make substantial changes in chip design, preferring to offer SoCs with vanilla versions of the A8.

Two of the most successful SoCs are the TI OMAP 3430 (the 65 nm chip used on Milestone) and OMAP 3630, the successor of 45 nm using the two used in the Droid.

Although capable of operating at up to 1.2 GHz overclocked (as in the case of Motorola Milestone), the OMAP 3430 has a very high electric console to these frequencies, which means that manufacturers have opted to use it only 550 or The 600 MHz OMAP 3630 is in turn made of a technique for 45 nm and is capable of operating at 1.0 GHz while maintaining a power consumption similar to their predecessors of just 65 nm 600 MHz It is a SoC that includes a processor PowerVR SGX 530 graphics, memory controller, 64 KB L1 cache and 256 KB of L2, signal processor, interfaces and so on:

These two chips have several variations, which retains the use of Cortex A8 as the processing unit, but vary the internal components in the bundle.Although TI has been the first to produce Cortex A8 SoCs based on the bulk, the chips of serious OMAP 3xxx can now be considered obsolete in comparison to competitors, as they are single-core SoCs and are still based on PowerVR SGX530, a graphics accelerator much less than the Hummingbird or the Snapdragon, with a limited 3D performance and no support for video decoding 720p and 1080p via hardware.

The main feature of the A8 (and the Scorpion, used in Snapdragon) over the older ARM11 is the fact that he is a dual-issue processor, which processes two instructions per cycle, compared to a single statement of ARM11. Roughly, the ARM11 provides an architecture similar to the 486 (albeit with better performance per clock due to the optimal set of instructions), while the Cortex A8 uses an architecture more similar to the Pentium and Atom.

For the next month, is expected to launch the OMAP 4xxx, a SoC-based dual-core Cortex A9, which also includes an updated graphics accelerator, the PowerVR SGX540. He will reach the market as a competitor for the Tegra 2, but this time is that IT is doing worse, arriving late at the match.

Qualcomm's Snapdragon

Unlike TI and Samsung, who have opted to use the Cortex A8 broke modifications, Qualcomm has decided to develop a proper design, the Scorpion, by combining components of Cortex A8 with other developed internally. Roughly speaking, the Scorpion and the Cortex A8 could be compared to the Phenom and Core 2 Duo Both are compatible with the same set of basic instructions and operate at frequencies similar, but differences in the architecture make the performance varies according to the task.

In general, the Scorpion provides about 5% more raw processing power that the Cortex A8 vanila and offers better power management functions.However, the processing unit is only one component of the SoC, which also includes the GPU, accelerators and auxiliary interfaces.

Devices such as the Nexus are based on 65 nm version of Snapdragon, although that is capable of operating at 1.0 GHz, includes a GPU Adreno 200, which is quite outdated by today's standards. Newer devices, such as Desire HD are based on 45 nm version of Snapdragon, that despite similar clocks, offer a GPU Adreno 205, considerably faster, combined with other improvements that made it competitive with the Samsung, well above Hummingbird the OMAP 3xxx, which virtually ceased to be used by manufacturers. The Snapdragon quickly became the dominant platform, equipping most phones released throughout 2010.

Samsung Hummingbird

Samsung was the last to break into the business of ARM SoCs for high-performance super-phones, entering into an uncomfortable position between the end of the reign of Snapdragon and the rise of Tegra 2.

Hummingbird is a 45-nm SoC, based on a modified version of the Cortex A8, which is capable of performing many of the commonly used binary operations using fewer instructions, resulting in gains of 5 to 10% compared to the original A8, surpassing the performance of a Scorpion in the same clock by a small margin in most tasks.

Another important factor is the fact that it includes a very powerful GPU, the PowerVR 540, which in addition to a strong performance 3D offers through hardware decoding for most video formats, unsupported even 1080p video, which can be viewed at native resolution via the HDMI port. He is also compatible with ARM NEON extensions, which offer gains compared to the processing of video and audio optimized for applications, similar to what we have in PCs with SSE instructions.

The Hummingbird's default clock is 1.0 GHz, as in S Galaxy, but he is capable of operating at higher frequencies, provided that the manufacturer knows equate the largest consumer of electricity. A good example is the Infuse 4G, which uses a Hummingbird operating at 1.2 GHz

Hummingbird is very similar to that used in Apple iPhone 4G A4 and the iPad. Apple licensed the design from Samsung, doing only minor changes within the chip, leaving the charge of the production partner.

nVidia Tegra 2

The initial release of Tegra, launched in 208, combining an ARM11 processor with a GPU powerful enough, that besides the strong 3D performance was able to record and display with 720p video processing in hardware, support for cameras up to 12 MP, output support HDMI and so on. Though he was a little weak in processing (due to the use of one instead of an ARM11 Cortex A8 SoCs or similar as in use today), he had a very strong set of features for its time. But he was being ignored by the makers of smartphones due to nVidia's decision in tow strong performance of the chip to Windows Mobile at a time when the interests of manufacturers were already in Android.

The comeback came with the nVidia Tegra 2, which inaugurated the era of multicore on smartphones, combining two ARM Cortex-A9 processor with a GPU more powerful than twice that of the original Tegra, which exceeds by a good margin of both the PowerVR GSX540 Hummingbird as the Adreno 205 Snapdragon, also supports the decoding of 1080p video via hardware.

The Tegra chip 2 has become the standard for high performance smartphone launched from the beginning of 2011 and was selected by Google as a reference for the chip tablets Android 3.0 (Honeycomb), which will cause it to be used also the first batch of tablet-based system.