If RAM lookups only cost 2 cycles they would beat L2 and L3 cache. The real problem is the speed of the RAM, not the distance, for now. When RAM gets a request

If RAM lookups only cost 2 cycles they would beat L2 and L3 cache. The real problem is the speed of the RAM, not the distance, for now. When RAM gets a request it can take many cycles to respond, sometimes as many as 50 or 60 before the first byte is returned. If you are smart you can request large sequential chunks and after the first bytes things come down to the the CPU very fast, but that initial hit is still something a lot of people optimizing algorithms are wrestling with.