Difference Between Apple A5 and A6 Processors

苹果A5与A6

A5 and A6 are Apple’s latest Multi Processor System on Chips (MPSoCs) designed targeting their hand held devices and introduced in their flagship products such as iPhone and iPad. Simply put, MPSoC is a computer with multiple processors on a single integrated circuit (aka chip). Technically, MPSoC is an IC that integrates components such as multiple-microprocessors, memory, input/output of a computer and rest that cater radio functionalities of a consumer electronic.

A5和A6 MPSOC的两个主要组件是基于ARM的CPU（中央处理单元，又称处理器）和基于PowerVR的GPU（图形处理单元）。虽然A5基于ARM的V7 ISA（指令集体系结构，设计处理器的起点），但A6基于同一ISA的Apple修改版本，称为ARM V7S。首次亮相，A5中的CPU和GPU是在被称为45nm和A6的半导体技术中构建的，A6是在32nm技术中构建的。尽管苹果设计了它们，但三星还是为苹果制造了它们。

Apple A5

A5 was first sold in March 2011, when Apple released its then latest tablet, iPad2. Later Apple’s iPhone clone, iPhone 4S was released equipped with Apple A5. As opposed to its predecessor A4, A5 had dual cores in its both CPU and GPU. A5’s dual core CPU is based on ARM Cortex-A9 processor (that uses ARM v7 ISA), and its dual core GPU is based on PowerVR SGX543MP2 graphics processor. A5’s CPU is typically clocked at 1GHz (although the clocking uses frequency scaling and, therefore, the clock speed can change from 800MHz to 1GHz, based on the load, targeting power saving), and its GPU is clocked at 200MHz. A5 has 32KB L1 cache memory per core and 1MB shared L2 cache. A5 comes with a 512MB DDR2 memory package that is typically clocked at 400MHz.

Apple A6

Apple, the trademark that is known for breaking traditions, broke its own tradition of releasing a major processor with its latest iPads when it decided to release Apple A6 processor with an iPhone (iPhone 5) in September 2012. As opposed to the popular believe that Apple will bring its quad-core CPU in A6, A6 was equipped with a dual-core processor similar to its A5 processor. However, A6 has a modified version of the ISA that was used in A5 and in-house processor architecture, known as Apple Swift (that is much better with latest vector processing, to say the least). Although A6 is equipped with a dual-core CPU similar to A5, (1) Apple claims that it is twice as fast as A5 and (2) some benchmark tests performed by third-party reviewers revealed that A6 performs much better than A5, due to its revamped instruction set and hardware architecture. The A6 processor is believed to be clocked at 1.3GHz, much faster than A5. The GPU used (that is responsible for the graphics performance) in A6 is a triple-core PowerVR SGX543MP3, as opposed to a dual-core GPU in A5. Therefore, the graphics performance of A6 is much better than that of the Apple A5 processor. A6 is expected to be shipped with a 32KB L1 private cache memory per core (for data and instruction separately) and a 1MB shared L2 cache, similar cache configurations to its predecessors. The A6 MPSoCs are also loaded with faster 1GB DDR2 (low power) SDRAMs.

A comparison Between Apple A5 and Apply A6

概括

总而言之，与Apple A5相比，Apple A6的性能在CPU和图形上的表现都要好两倍。尽管新技术支持更快的时钟速率和更好的硬件体系结构，因此可以加速CPU，更快的时钟速率和额外的核心启用了GPU中的加速。除了加速外，A6中的其他内存还将帮助最近在Apple Store中出现的饥饿记忆应用程序。