Chip design firm ARM today announced the eighth generation of its ARM Instruction Set Architecture (ISA). The ARMv8 ISA extends the current ARMv7 architecture to include support for 64-bit addressing. The company said that this move would enable the architecture to be used in servers and other enterprise roles, bringing ARM's low-power advantage to a market that's increasingly challenged by power consumption and energy efficiency.
ARMv7 provides a 32-bit virtual address space, coupled with a maximum of a 40-bit physical address space. This allows ARMv7 designs—such as the Cortex A8 and Cortex A9 designs that power many smartphones, including Apple's iPhone 4S—to give each application its own private allocation of 4GiB memory, and potentially to address a total of 1TiB physical RAM.
For traditional ARM roles, including smartphones, 4GiB is plenty, but the company wants its architecture to break out of its current embedded niche. 64-bit virtual addressing allows applications to easily handle much more data, making it a must for applications such as databases and scientific data processing. ARMv8 will enable ARM chips to take on these new roles while still retaining the low power consumption that has made ARM processors so widespread in smartphones and tablets.
64-bit software is also becoming more common on the desktop, and it enables programs such as Adobe Photoshop and Microsoft Excel to efficiently process much larger images and spreadsheets, respectively. With Windows 8 including support for ARM processors, ARM may start to make inroads on the desktop market, too.
The ARMv8 ISA describes the instructions and behavior of 64-bit ARM chips, allowing developers of operating systems and compilers to start making the changes necessary to support these chips. ARMv8 processors will be able to operate in either 32-bit or 64-bit mode, and will continue to offer features found in ARMv7 designs such as virtualization support, Neon SIMD instructions, and the TrustZone security feature.
Hardware designers will have to wait a little longer. ARM plans to release the first chip designs that support ARMv8 next year, and expects prototype systems using these designs to emerge in 2014. One early customer of the designs is likely to be Hewlett-Packard: Bloomberg is reporting claims that the company is planning to ship ARM servers.