carry on or check in.  prob too big for carry on.  find an old pc box big enough.  you may need to pay extra if three dimensions exceed airline limit.  remove gpu and take it w you but show it to security check in.
We want to transport our Alienware Area-51 R4 on airline with us. But can't seem to find a luggage large enough to fit it in. What do you guys suggest? 
Area-51 R4, we want to transport on airline