270x - 7950 refresh with 1GB of vram less
EDIT: Looking at other responses this may just be a 7870!
280x - 7970 Ghz edition refresh
290x - the only genuine 'new' Hawcard
There seems to be some confusion about what the 270x will be:
R270 is HD 7950 re-boxed and these shall be reference design in beginning and prices from £170 region, so same as our lowest price 7950's. So OcUK is already at the new price, the newly boxed R270's will arrive middle-end October.
R280X is the HD 7970 GHz re-boxed and these shall be reference design in beginning and prices shall be around £230 region, so same again as our lowest priced 7970's. This makes our current Asus 7970's a bargain as they are TOP and Platinum cards, the equivalent of these in R280 X shall be in the £250-£300 region and available in their R280 X packaging around end of October.
R290 X unfortunately I cannot release pricing or specification info yet, but price wise its similar to GTX 780 but slightly faster, right now, of course AMD could change the launch price at any time.
So is this the conversion?:
9970 -> R290X
7970 -> R280X
7950 -> R270X