4ns.. hhmmm I have never heard of Samsung PC3500 4ns DDR, unless it was under lock and key and top secret.. I doubt it.. Here's my advice.. Buy it only if they let you return that RAM without any restocking fee. Otherwise don't do it. I could be wrong, but 4ns DDR ram for the PC sounds a bit too premature. Again I could be wrong, buy it only if you can return it without a fee.. good luck.. also you might want to ask the dealer to remover the heatspeader if there is one to see if they are indeed 4ns chips. If it doesn't come with a heatspeader, then it's probably not good.. Everyone who knows RAM knows that PC3500 RAM gets very very hot and needs a heatspeader to ensure it lasts.