[AmityvilleHams]

Definitely separate them, they'll both need their own properly sized cage. Hamsters of any species do far better housed on their own as in the wild they don't really exhibit true social behavior as much as they sometimes will stay together in mixed sex combinations for breeding purposes and as such two males or two females or even group housing can be incredibly stressful for them. It's quite different comparing them to a species like guinea pigs or rats where social housing is beneficial and a necessity, while with hamsters of any species they often do end up fighting and can cause serious harm to each other(along with chronic stress and other issues).