280x is fine as 280x. Yet another rehash of a 2012 chip in 2015 is one too many in my book
380X sounds like a full Tonga, not a refresh of a 280X.
Sooner or later 280X/290/290X will all dry up. In Canada, the UK, and as I understand it most of Europe, you basically can't even find these cards anymore. AMD will need something to compete with GTX950/960/960 4GB cards.
NV currently has a massive 50% performance gap between its 960 and 970 cards.
Without spending any $$ on GPU redesign, I can see how 370X (1.1-1.15Ghz Pitcairn) and 380X (Fully unlocked Tonga) can find buyers.
TechPowerup was one of the few sites that had the b*lls to state what many people have been saying since GTX960 launched in Jan of 2015:
"NVIDIA simply cannot get the pricing of its sub-$300 lineup right and continues to offer nothing compelling until the $310 GeForce GTX 970. The company may yet make a ton of money with their mid-range line-up, but that's only because of its better sales-force." ~ TPU
AMD should have taken advantage of NV's horrible price/performance and product positioning in the sub-$300 space but they were asleep at the wheel for the last 9 months, just waiting until all the 285/280X/290/290X cards sell out. These cards have long sold out in some worldwide markets but AMD hasn't provided a proper replacement in the $200-300 space.
If a full Tonga with higher clocks can get 125-130% on that TPU chart at 1080P, NV will have to introduce a 960Ti or lower prices on 960 4GB to compete. The crazy part is R9 285 Tonga came out September 2, 2014 and it's been more than 12 months but AMD still wouldn't launch a full 2048 shader Tonga with 4GB of VRAM. Talk about dropping the ball.
I can't see how prioritizing the full Tonga for Apple was a great move because most of those products sell in small numbers vs. the $200-250 desktop discrete GPU market segment which probably gets 20%+ of all GPU sales.