The abbreviation ARM stands for Advanced RISC Machines and refers to a processor design developed by the British company ARM. In principle, the development of the ARM processors began in 1983, but the acronym stood for Acorn RISC Machine at the time.
Processor boxes
The first fully ARM-based computer was the Acorn Archimedes in 1987, but ultimately could not get through to IBM-compatible PCs. In 1990 ARM Limited was founded as a joint venture between Acorn, Apple and the processor manufacturer VLSI, which took over the production of the processors. Apple was with the party, since the Newton was equipped with an ARM CPU. Apple, however, has no longer held shares in ARM Holding for a number of years, so the company is called today.
Apple's ARM processors: own cores with PowerVR-GPU
ARM processors were used primarily in set-top boxes and in the embedded area in the following years. In 1998, ARM was listed as a holding company. The company is no longer manufacturing processors, but is a pure development studio, which grants licenses to other manufacturers who are allowed to build processors based on the ARM architecture.
Samsung Exynos: From Mali to PowerVR
ARM has various licensing models, ranging from Blaupausen for complete processors or processors to IP licenses, on the basis of which the CPU manufacturers can develop independent designs. This is especially the case with large processor manufacturers such as Samsung, Qualcomm, Texas Instruments or Apple.
Nvidia Tegra 3 and Tegra 4: ARM-SoCs from the graphics specialist
The ARM processors in current tablets or smartphones all belong to the SoC type (system-ona-chip), so they are highly integrated, compact and therefore economical components, in which the "die" next to the CPU cores with the memory controller Graphics processor (GPU), the audio processor and peripheral units such as the interfaces to the display and touch screen, the WLAN controller, a GPS module or the USB controller. Often a 3G or even LTE module is also integrated.
Since all these components communicate via well-defined bus systems, ARM processors can be designed like a kit of different functional blocks, which can be developed by third parties or licensed by third parties. For example, for most ARM Exynos ARM processors, Samsung has been using ARM's Mali GPUs, but the Exynos 5 Octa used a PowerVR GPU, and Apple also uses a PowerVR graphics in its own ARM processors Code>
For the first three generations, Apple used Samsung processors. With the acquisition of ARM licenses and especially the acquisition of the Californian processor manufacturer P.A. Semi rose Apple itself into the processor development. The first proprietary ARM-based processor was the A4, which was used in the iPhone 4 and the first iPad. Samsung has only been a subcontractor for Apple.
Currently Apple is at the A6X as the current top model among its own ARM processors, it is used in the current iPad of the fourth generation with Retina display. The A6X, produced in a 32 nanometer process, is a processor developed by Apple itself with two CPUCores and a PowerVR SGX 554MP4 as graphics processor. The PowerVR graphics in the A6X consist of four cores, in the iPhone 5 works as the processor of the A6 with lower clock frequency and the triple-core graphics SGX 553MP3
Since Apple is very closed in technical internals, the type of ARM cores and the clock frequency of the processors can only be speculated. But it is to be assumed that the A6 and A6X are higher clocked and thus more powerful variants of the predecessors A5 and A5X, which are based on the Cortex A9 of ARM. The higher clock was possible by switching from 45 to 32 nanometer transistors. The smaller transistors can switch faster at the same core voltage and thus achieve a higher clock frequency.
The A5 has now also undergone a Die-Shrink on 32 nanometers and is thus at the same power with less power. It is used in the iPad 2 and the iPad Mini. The GPU is a PowerVR GSX 543MP2 with two cores.
The PowerVR GPU in the Apple processors is a later descendant of the PowerVR chips, which were found at the end of the 90s on the then unsuccessful PC graphics card Kyro II and the Sega console Dreamcast. They use the then developed Tile-based-Redering-method, which also ensures a relatively high 3D performance even with the narrow memory bandwidth of the low-energy ARM processors. Other GPUs in ARM processors rely on this technique.
Among the GPUs for ARM processors, the Quadcore-PowerVR used in the Apple A6X is certainly at the forefront, as the 17.2 fps at the OpenGLBenchmark GFXBench 2.7 (T-Rex HD Offscreen) occupy. The PowerVR GPUs of the 5X series only support OpenGL ES 2.0, OpenGL 3.0 ES comes with the new GPUs of the sixth generation.
Samsung also has a powerful PowerVR-GPU with the new Exynos 5 Octa. In the Octacore-SoC is a SGX 544MP3 as GPU with the cores. The Samsung uses the big.Little technology developed by ARM for the CPU cores in this 8-core processor.
Qualcomm Snapdragon: With its own Adreno graphic
It basically consists of two quad-core processors: the one with fast, but hungry 1.8 GHz A15 cores and is responsible for computer-intensive applications such as games or HD videos. The basic features of the operating system and modest apps run on four economical A7 cores at 1.2 GHz clock frequency to allow for a proper battery life.
To accommodate this on a chip, which is not too big, Samsung uses a 28-nanometer for the production of the processor for the first time - instead of the previous 32-nanometer method. With its fast A15 cores and the PowerVR graphics, devices with the Exynos 5 Octa will also deliver very good values in 3DBenchmarks. Whether it's enough to depend on the Apple A6X, Qualcomm Snapdragon 800 or Nvidia Tegra 4 remains to be seen.
ARM compared to Intel mobile processors
You can not test it at present, because the Galaxy S4 with the Exynos 5 Octa is not offered in the United States, because the processor lacks the desired LTE support. With the Exynos 5 Dual and the Exynos 4 processors with two or four cores, Samsung uses slower Mali GPUs from ARM. The Mali GPU was originally developed by the Norwegian manufacturer Falanx, which took over ARM in 2006.
Nvidia had with the ARM processor Tegra 3 mainly success with Android tablets, also the sales ramp Nexus 7 is based on the Nvidia processor. However, the Tegra 3, which was introduced at the end of 2011, is no longer competitive in comparison to the top models from Apple, Samsung and Qualcomm. The Tegra 3 is also only in the midst of 3D performance.
This is why Nvidia has introduced the Tegra 4 with a modern successor, which now has four Cortex A15 cores and 1.9 GHz and has a significantly stronger GPU with 72 shaders, the Tegra 3 still needs 12 shaders .
About RISC CISC
Faster atom on the horizon
In addition to the Tegra 4, Nvidia also has a Tegra 4i with integrated LTEModem, four Cortex A9 cores and a GPU with only 60 shaders. This much smaller chip is probably primarily intended for smartphones. The "big" Tegra 4 can also be combined with an LTE modem from Nvidia, which however then occupies as additional chip space on the main board. Confusing: Nvidia designates the shaders as cores.
Compared to other manufacturers' ARM GPUs, however, the number of GPU cores can not serve as an indication of performance because they differ significantly in their architecture. Unlike the GeForce chips for notebooks and PCs, the GPUs in the Tegra-SoCs only support OpenGL 2.0 for embedded systems. In 3D performance, Nvidia is back with the Tegra 4 in a league with the top ARM processors from Apple, Samsung and Qualcomm.
Nvidia also uses a similar trick to Tegra 3 and Tegra 4 as Samsung with the Exynos 5 Octa to achieve a longer battery life. In doing so, tasks that do not require a strong CPU are assigned to a single, economical companion core that handles them while the four powerful cores are completely shut down. The Tegra 4 is manufactured at TSMC in 28 nanometer technology, the Tegra 3 is still a 40 nanometer chip.
Qualcomm is using the ARM processors of the Snapdragon series to develop proprietary GPUs with the name Adreno. The Adreno 330 graphics are used as GPUs in the Qualcomm top model Snapdragon 800 with four cores. It is the first ARM GPU to offer OpenGL ES 3.0 support, which is also used by Unity3D, according to Qualcomm, Unity3D is the most important engine for mobile 3D games.
Current benchmarks such as the GFXBench 2.7 or the Futuremark 3DMark currently use only OpenGL ES 2.0 for ARM devices. Nevertheless, 3D performance is here comparable to that of the Apple A6X or the Nvidia Tegra 4. Under the Snapdragon 800 is the 600, which is equipped with a somewhat slower Adreno 320 GPU, but also supports OpenGL ES 3.0
As a CPU component, Snapdragon 600 and 800 are based on ARM-based Krait cores with four processor cores. At the 800, they operate at 2.3 GHz and the 600 at 1.9 GHz clock frequency. In addition, the Snapdragon 800, in contrast to the 600, also supports USB 3.0, a novelty in ARM processors. Qualcomm comes with the Snapdragon processors in contrast to the Samsung Exynos 5 Octa or the Nvidia Tegra 4 without additional low-power cores. Instead, Qualcomm uses a technique called Asynchronous Symmetric Multiprocessing, in which the frequency of the individual cores can be throttled to achieve a longer battery life in less demanding applications.
When evaluating the performance of ARM processors, one must not forget that they are trimmed to a low power consumption and therefore mobile CPUs such as Intel's Haswell can not reach the water. So a Sony VAIO Duo 13 with Core i7-4500U is at least three times as fast as an Apple iPad of the fourth generation. However, power consumption and, above all, the price of a core processor are naturally higher. The current Intel Atom Z2760 as direct competitors are clearly superior to the ARM top models. However, Intel wants to counteract a new Atom generation at the beginning of 2017.
In the mid-1990s it seemed as if RISC processors could also conquer the desktop PCs. That didn `t work. Today, they dominate mobile devices.
ARM processors carry the abbreviation RISC already in the name: ARM stands for Advanced RISC Machines and thus also designates the architecture of these processors. The acronym RISC (Reduced Instruction Set Computer) refers to processors, the
With a simple and hard-wired command set, as opposed to the classic CISC (Complex Instruction Set Computer) processors, where the commands are loaded as microcode.
The advantage of RISC processors was their higher clock frequency. Thus a DEC Alpha in 1997 could work with 533 MHz, while an Intel Pentium could only run with 233 MHz. Even from Windows NT, there was at that time a version for the Alpha. In practice the difference is however since the Intel Pentium Pro lifted. All Intel and AMD processors have been working as RISC CPUs since then. The x86 instructions are translated into RISC commands via an upstream decoder. This also led x86 CPUs to higher clock rates. Apple has kept the RISC architecture with the PowerPC still loyal until 2006.
Intel is making pressure: the new Silvermont Atom is not only designed for faster and more cost-effective Windows 8 tablets, but is intended to make ARM competition.
Atom in 22-nanometer technology: With the upcoming Silvermont generation of the Atom processors Intel wants to gain a foothold in the tablet and smartphone market. In the new Intel SoCs instead of two up to four cores and as a GPU for tablets the HD 4000 known from Ivy Bridge with significantly better 3D performance than the previous models with older PowerVR graphics. The new atom is produced in 22 nm technology and should be more economical than the current 32 nanometer atom. They are expected to be launched in early 2017.
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