Be carefull with the new offering from AMD as they tend to sell refurbished/reused/repurposed old chips in the lower end and mid tier cards.
They just change the name and voila.
Be sure which chip is on, EXACTLY.
280x card for example uses "Tahiti XTL" chip, being a slightly upgraded, rebranded Radeon HD 7970 GHz Edition.
Don't get me wrong, the card is phenomenal, but it is old tech.
290x is NEW tech (when these came out) based on "Hawaii XT" chip.
So you see, you would think that the series R9 X200 chips are all the same, just lower clockspeed and whatnot etc.
No no, see Tahiti is old stuff they cram on us unawares, Hawai is the new stuff you should pay attention, as it is the only chip that had improved and new features added to it.
This warning is to those who intend to buy the new upcomming x300 series cards.
Make sure you buy NEW tech, not old rebranded chips which were superseded.
So:
HBM Stacked Memory is up to 9X Faster Than GDDR5 – Coming With AMD Pirate Islands R9 300 Series
Make sure that your chosen cards actually empploys chips that are NOT rebranded from Fiji, Tahiti or any previous tech. And that they have HBM instead of GDDR5 memory.
Bermuda GPU is the tech you want if you shell the bucks for the high end card.
If you intend to buy medium tier, then this warning does not concern you. You will get old tech rebranded, and there is nothing you can do.
Bermuda is the replacement for Hawaii (R9 295X2, R9 290X, R9 290), Fiji is the replacement for Tahiti (R9 280X and R9 280) and Treasure Island is the replacement for Curacao (R9 270X and R9 270)
And if you buy anything less than 390x you are buying old tech.
Damn you AMD.
You are better off with Nvidia if it is anything less than 390X realy.