Physics processing unit

A physics processing unit (PPU) is a dedicated microprocessor designed to handle the calculations of physics, especially in the physics engine of video games.

Examples of calculations involving a PPU might include rigid body dynamics, soft body dynamics, collision detection, fluid dynamics, hair and clothing simulation, finite element analysis, and fracturing of objects.

The idea is that specialized processors offload time consuming tasks from a computer's CPU, much like how a GPU performs graphics operations in the main CPU's place. The term was coined by Ageia to describe its PhysX chip. Several other technologies in the CPU-GPU spectrum have some features in common with it, although Ageia's product was the only complete one designed, marketed, supported, and placed within a system exclusively as a PPU.

An early academic PPU research project named SPARTA (Simulation of Physics on A Real-Time Architecture) was carried out at Penn State and University of Georgia. This was a simple FPGA based PPU that was limited to two dimensions. This project was extended into a considerably more advanced ASIC-based system named HELLAS.

February 2006 saw the release of the first dedicated PPU PhysX from Ageia (later merged into nVidia). The unit is most effective in accelerating particle systems, with only a small performance improvement measured for rigid body physics. The Ageia PPU is documented in depth in their US patent application #20050075849. Nvidia/Ageia no longer produces PPUs and hardware acceleration for physics processing is now supported through some of their graphics processing units.

...
Wikipedia