By and large this would be a topic of interest for most of us including me when I started to explore this space. Before we dwell into the numbers let’s first understand some basic differences between 2 architectures. Beyond being CISC and RISC let’s look at the important differences from MySQL perspective.
- Strong vs Weak memory model (weak memory model needs proper memory barrier while writing lock-free code).
- Underlying hardware specific specialized instructions. For example: both now support crc32c hardware instructions but being low-level they are different ways to invoke them. For more differences checkout for x86-SSE/ARM-ACLE.
- Cache Line differences. Most of the ARM processors tend to use bigger cache lines (128 bytes for all caches or a mix of 64/128 bytes).
- Other sys-call level differences like: absence of PAUSE instructions with ARM and substitute instruction with very low latency …