The main reason for virtual addresses/TLB is to prevent processes from accessing each other's memory (isolation). For optimization I'd say the page size (64 kB) is a secondary concern. It's handled in hardware (TLB) with the OS only occasionally filling up the mapping. You want to avoid that happening, but you probably should worry more using whole cache lines (64 bytes) instead, and beyond that just keep memory access local (multiple cache hierarchies) and predictable (pre-fetcher).