Apple A5 vs 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.
The two major components of both A5 and A6 MPSoCs are their ARM based CPUs (Central Processing Unit, aka processor) and PowerVR based GPUs (Graphics Processing Unit). While A5 is based on ARM’s v7 ISA (instruction set architecture, the starting point in designing a processor), A6 is based on an Apple modified version of the same ISA, known as ARM v7s. At debut, the CPU and the GPU in A5 were built in the semiconductor technology known as 45nm and A6 were built in 32nm technology. Although Apple designed them, Samsung manufactured them for Apple.
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, 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
iPhone 4S, 3G Apple TV
Not available yet
ARM Cortex-A9 (dual core)
Apple Swift (dual core)
CPU’s Clock Speed
0.8-1.0GHz (frequency scaling enabled)
PowerVR SGX543MP2 (dual core)
PowerVR SGX543MP3 (triple core)
GPU’s Clock Speed
32kB instruction, 32kB data
32kB instruction, 32kB data
512MB DDR2 (LP), 400MHz
1GB DDR2 LP, 533MHz
In summary, Apple A6 is promised to perform as twice better in both CPU and graphics compared to Apple A5. While, the new technology used that supports faster clock rate and better hardware architecture enabled the speedup in CPU, faster clock rate and the additional core enabled the speedup in the GPU. In addition to the speedup, additional and faster memory in A6 will help memory hungry applications that are emerging in the Apple Store recently.