CPU architecture developer ARM has the processor core Cortex-A 78 C as a modification of the previous Cortex-A 78 or Cortex-X1 (again an adapted A 78) presented. The Cortex-A 78 C is architecturally very similar, but can be configured in a cluster of 8 instead of a maximum of 4. ARM is aimed at notebooks with Windows on ARM and Chrome OS.

For the four additional Cortex-A 78 C-cores falls from the second CPU network from more efficient Cortex-A 55 – Cores gone – the maximum number of cores does not change. Since corresponding processors consequently consume more power at low load without the big-little principle, ARM sees the Cortex-A 78 – Design not for smartphones.

Instruction set extensions preferred Extensions to the instruction set architecture are also new (Instruction Set Architecture, ISA), which actually only appear with ARMv8.3, ARMv8.4 and ARMv8.6. This includes support for so-called Pointer Authentication Code (PCA), which is intended to prevent malware attack techniques such as Return Oriented Programming (ROP) and Jump Oriented Programming (JOP). PCA makes it more difficult to use code fragments from other programs that are already in the main memory (RAM).

ARM gives manufacturers considerable freedom in terms of chip design. If you license the Cortex-A C core for your own processor, you can combine a maximum of eight CPU cores, with fewer But also six power requirements, for example. The level 1 caches for data and instructions are 32 to 64 KByte per core and the L2 cache 256 to 512 KByte. L3 cache is optional and can be used with KByte to 8 MByte – ARM recommends the full expansion stage for high performance. 3D calculations are performed by a Mali-G 64 GPU.

Block diagram for Cortex-A 78 C: Corresponding CPUs can be designed largely modularly.

(Image: ARM)

The complete A 78 – family is designed for structures of 5 nanometers. The first offshoots are probably Qualcomm’s upcoming Snapdragon 875, for which the first benchmarks on the Chinese website Weibo and Samsung’s Exynos 1080, to which the manufacturer himself first details about Weibo shared. Both mobile processors are intended for high-end smartphones and should come with Cortex-A 78 or Cortex-X1 cores. (mma)