Prefetching brings data into the cache before it is expected by the processor, thereby eliminating a potential cache miss. There are two major prefetching schemes. In a software scheme, the compiler predicts the memory access pattern and places prefetch instructions into the code. In a hardware scheme the hardware predicts the memory access pattern and brings data into the cache before required by the processor.

This paper proposes a hardware prefetching scheme, where a second processor is used for prefetching data for the primary processor. The scheme does not predict memory access patterns, but rather uses the second processor to run ahead of the primary processor so as to detect future memory accesses and prefetch these references.