Hexus posted a review on the AMD Radeon R9 Nano
A quote from the article:
The small-form-factor king emerges. AMD launched the premium Radeon R9 Fury X graphics card back in June this year. Designed to compete with the best consumer graphics Nvidia has to offer, Fury X uses a scaled-up GCN architecture and, for the first time, HBM memory for increased bandwidth and potential to build smaller cards.AMD Radeon R9 Nano Review @ Hexus
And while the liquid-cooled Fury X puts AMD back in the big league as far as all-out performance is concerned it's not quite the GeForce-thrashing card that some expected. Of rather more interest to many is what AMD can do with the power efficiencies and massively reduced form factor of HBM memory, and AMD teased the appropriately named Nano a short while back.