Difference Between Apple A5 and A5X Processors

Apple A5 vs A5X Processors
 

Apple A5 and A5X are Apple’s latest System on Chips (SoC) designed targeting their hand held devices. In a Layperson’s term, a SoC is a computer on a single IC (Integrated Circuit, aka chip). Technically, a SoC is an IC that integrates components such as microprocessor, memory, input/output of a computer and other systems that cater electronic and radio functionalities.

The two major components of A5 and A5X SoCs, rather MPSoCs (Multi Processor SoCs) are their ARM based CPU (Central Processing Unit, aka processor) and PowerVR based GPU (Graphics Processing Unit). Both A5 and A5X are based on ARM’s v7 ISA (instruction set architecture, the one that is used as the starting place of designing a processor). The CPU and the GPU in both A5 and A5X are built in the semiconductor technology known as 45nm (not verified for A5X). Although Apple designed them, Samsung manufactured them on the request made by Apple.

Apple A5

A5 was first sold in March 2011, when Apple released its then latest tablet, iPad 2. Later Apple’s recent 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. Therefore, technically Apple A5 is not just a SoC, but an MPSoC (Multi Processor System on Chip). A5’s dual core CPU is based on ARM Cotex-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 533MHz.

Apple A5X

The new iPad (aka iPad 3 or iPad HD), the first consumer electronic device that will be equipped with A5X MPSoC will be first sold in the mid of March 2012 (during the course of this week). During the new iPad launch event on 7^th March 2012, Apple revealed that they will be using Apple A5X processor to drive the device. Apple A5X has a dual core CPU like A5 and therefore not going to perform very different compared to its previous A5 MPSoC. It is worth to note that, this is opposed to the previous belief that Apple will use a quad core processor, the trend of 2012 MPSoCs, for its new iPad. Based on the information leaked up to now, Apple will clock its A5X CPUs at 1.2 GHz as opposed to 1GHz in A5. Although A5X has a dual core CPU, the GPU used (that is responsible for the graphics performance) is a quad core PowerVR SGX543MP4. Therefore, the graphics performance of A5X is going to be theoretically doubled compared to Apple’s A5 processor. In fact, the “X” in A5X stands for graphics. Therefore, A5X is a high end graphics processor that is expected to support the new iPad HD graphics (the retina display that Apple is introducing in the new iPad, the first in tablet PCs). A5X 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. It will also be expected to be packaged with a 512MB memory.

A Comparison Between Apple A5 and Apply A5X

Summary

In summary, Apple A5X is expected to perform far better in its graphics compared to Apple A5 while performing little better in regular computation compared to A5 due to its faster clock frequency. More comparison based on benchmarks will only be possible after A5X’s release and therefore we need to wait until it’s released in the new iPad3 later this week (16 March 2012).