My experience is that memory mapping the file is not faster than reading it in big chunks into an already mapped, pre-allocated buffer. You're going to be inti

My experience is that memory mapping the file is not faster than reading it in big chunks into an already mapped, pre-allocated buffer. You're going to be intially page faulting every 4096 bytes if you mmap the file. The fact that you're accessing the mapped range sequentially in this case may help, I guess.