Looks like AMD just can't catch a break. TweakTown confirms the rumor from FUD Zilla that there will be two Fiji cards, the single-GPU Radeon R9 390X 4GB and the dual-GPU Radeon R9 395 X2 with 8GB RAM.
TweakTown claims the dual-GPU variant will be able to beat the GeForce GTX Titan X while the Radeon R9 390X won't be able to outperform it. The bad news however is that yields of the new High Bandwidth Memory (HBM) are said to be poor and the site claims that as a result of this, we will only see a very limited supply of Radeon R9 390 series cards through the end of the year.
If the rumor is correct, AMD's gamble on being an early adopter of HBM may turn out to be yet another major mistake.