Apple A7 vs Apple A5

Apple A7

The Apple A7 is a high-end ARM SoC launched in September 2013 alongside the iPhone 5S. The chip can also be found in the iPad Air. It is one of the first ARM SoCs to implement the 64-bit ARMv8 ISA. The two CPU cores are clocked at 1.3 GHz (iPad Air: 1.4 GHz) and are based on Apple's Cyclone architecture. Furthermore, the chip also integrates a PowerVR Series 6 (Rogue) G6430 GPU and a 2x 32-bit LPDDR3 memory controller.

Architecture

Cyclone is the successor to the Swift architecture, which was used in the previous generation Apple A6/A6X SoCs (iPhone 5/iPad 4). The architecture is likely still a superscalar out-of-order design, but with significant revisions. Besides the new ARMv8 ISA, the chip offers various cryptography extensions (AES, SHA), extended registers and improved SIMD instructions. In combination with many other improvements like larger L1 caches and other optimizations, the performance per clock has been increased by about 50 percent. Even greater gains can be reported using 64-bit software.

Performance

Despite the low clock speed and only two CPU cores, the Apple A7 competes with other high-end ARM SoCs such as the Qualcomm Snapdragon 800. In software with poor parallelization like browser benchmarks, the A7 can outperform the entire ARM competition and be on par with the AMD A4-5000 or Intel Atom Z3770.

Graphics

The SoC integrates a PowerVR Series 6 (Rogue) G6430 GPU with 4 clusters. The G6430 offers more than twice the computing power of the SGX543MP3 in the Apple A6 and supports OpenGL ES 3.0 for the first time. The exact clock rate has not yet been confirmed, but it is probably in the 400 MHz range resulting in more than 100 GFLOPS. In the iPad Air, the GPU is clocked slightly higher at presumably about 450 MHz. Compared with other mobile graphics solutions, the G6430 performs similar to the tablet version of the Snapdragon 800 / Adreno 330 and is thus one of the fastest GPUs in its class. Therefore, even the most demanding iOS games of 2013 will run fluently.

Power Consumption

The A7 can be found in the Apple iPhone 5S, which offers a very long battery life despite its relatively low battery capacity. The chip is produced in a 28nm HKMG (High-K Metal Gate) process by Samsung and should have an estimated maximum power consumption of less than 2 - 3 W. In the iPad Air, the SoC should have a slightly higher TDP due to higher clock rates and less throttling.

Apple A5

The Apple A5 is a dual-core processor that contains two Cortex A9 cores. Each core is max. clocked at 900 MHz. Furthermore, the A5 integrates a relative fast PowerVR SGX 543MP2 graphics card and 512MB ram (in the same package for the iPad 2). Apple states a maximum of 2x the performance compared to the previous single core Apple A4.