A new computer architecture has appeared: 64-bit ARM systems (also known as "ARM64" or "AArch64"). While AArch64 is showing up in cell phones and tablets, it is also poised to pounce on the datacentre. Most of the work of porting core software to AArch64 has been completed, and at this point, just about everything that runs on x86_64 Linux systems will run an AArch64 systems. However, the x86_64 architecture has been around for many years, and software has been well-optimized to work on that architecture; but AArch64 is relatively new, and it may be possible to get better performance with additional tuning and optimization.