Yeah I can see that to be true. If you have more address spaces to access (16GB vs. 8GB), then your latencies are going to be a little higher because you have to search through all that space to read and write the data. One thing that could probably help you is to make sure you buy a kit that would populate all of the memory slots. That way you could take advantage of dual, triple, or quad channel memory accesses (whatever your motherboard supports).