The CUDA programming model, which is based on an extended ANSI C language and a runtime environment, allows the programmer to specify explicitly data parallel computation. NVIDIA developed CUDA to open the architecture of their graphics accelerators to more general applications, but did not provide an efficient mapping to execute the programming model on any other architecture. This paper describes Multicore-CUDA (MCUDA), a system that efficiently maps the CUDA programming model to a multicore CPU architecture.