Well since Thomas never replied I'll do it myself. RtlCopy is, in fact, the faster variant. I was about to change all the Nt code but Thomas did it.
Oops, in fact I did reply. I just used the wrong email address so it never got through :(
Yes, RtlCopyMemory <=> memcpy doesn't handle overlapping regions and is faster. RtlMoveMemory <=> memmove handles overlapping regions.
- Thomas