What is a Register File?

The register file of the Streaming Multiprocessor is the primary store of bits in between their manipulation by the cores .

Like registers in CPUs, these registers are made from very fast memory technology that can keep pace with the compute cores , about an order of magnitude faster than the L1 data cache .

The register file is split into 32 bit registers that can be dynamically reallocated between different data types, like 32 bit integers, 64 bit floating point numbers, and (groups of) 16 bit or smaller floating point numbers. These physical registers back the virtual registers in the Parallel Thread eXecution (PTX) intermediate representation.

Allocation of physical registers to threads in Streaming Assembler (SASS) is managed by a compiler like ptxas, which optimizes register usage by thread blocks .