Some GPU news comes today from the AMD camp where we are hearing rumors that AMD’s Radeon 390X might ship with 8GB of High Bandwidth Memory (HBM). Now this sounds great when you take into account the fact that HBM has some serious muscle behind it (128GBps per memory chip). AMD could technically leapfrog nVidia’s new monster the GeForce Titian X with 12GB of memory onboard. The problem is that some of the information that is floating around does not seem to add up.