What is the most common architecture used for CPUs today?

The most common architecture for CPUs today is x64 or 64-bit. This architecture has largely supplanted the older x86 or 32-bit architecture across various computing platforms because it offers significant advantages in terms of performance and capabilities.

The x64 architecture allows for a larger addressable memory space, enabling systems to utilize more than 4GB of RAM, which is a limitation of the 32-bit x86 architecture. This increased memory capacity is crucial for modern applications that require substantial resources, such as high-end gaming, video editing, and data processing tasks. Moreover, many operating systems and applications are now optimized for 64-bit architecture, which leads to overall better performance when running on compatible hardware.

While ARM is widely used in mobile devices and is gaining traction in desktop markets due to its power efficiency, x64 has a strong foothold in general-purpose computing environments such as desktops, laptops, and servers. The x86 architecture, although still in use, is primarily found in legacy systems, hence the preference for x64 in contemporary CPU designs.

SPARC is a RISC (Reduced Instruction Set Computing) architecture that is predominantly used in specific enterprise environments rather than general consumer computing, making it less common compared to x64.