[jcranberry]

If the data is contiguous in memory and frequently accessed it will almost certainly make its way into L1 cache and be there for the life of the program.

If the data is not contiguous it could make the CPU's life much harder.

There's also the matter of program size (the amount of instructions in the actual program) and whether the program does anything which forces it to go lower cache levels or RAM.

There are intrinsics for software prefetching such as __mm_prefetch, but those are difficult to use such that they actually increase you're performance.