Part of the problem with the nomenclature is the median price for a graphics card is bottlenecked in a range... $89 - $250.. And all except the high end, you haven't seen the needle move much in terms of performance from a graphics card that's 2 years old.. granted, the deck plates rearrange: Direct-X, OpenGl--- and then throw in the shader model, textels, fill rates,stream processor counts, processor frequency, ram frequency, and resolutions upto 4k, as benchmarks to say whether a "game" will work properly or be compatible.. Ugh, it's a mess.. but all-in-all you see not much innovation and alot of shifting and confusion of standards..
Right now game companies are afraid to stray from the universal Direct-X 10/11 holy grail for fear of losing customers but for how long?
Both Intel and Amd have DELAYED introducing products until game companies commit to giving customers a reason to buy new graphics cards... (chicken & the egg). Obviously, you don't need a new video card to play 1080p video, play soletaire, or do desktop word processing. At last count, AMD/ATI has a slight edge on value for the mid-grade video cards in the $89 - $249 range.
If you want some comparisons...
amd 5xxx & 6xxx range was comparable to nvidias 7000 series.. and the new 7000 and 8000 series (AMD) are comparable to the new 3 digits we have today (confused yet?).. I think since the 6600 nvidia's they've caught up to DX-11 compatability.. But we're talking about 3+ year old cards. vs cards released in the last 6 - 12 months. Consumers are quick to orphan older generations of graphics cards in favor of new ones, however you will likely SKIP a few generations of graphics cards between systems (or rebuilds & upgrades.. as these product cycles are 5 - 10 years for a new pc vs 12-24 months for graphics cards). They are starting to get the message to slow innovation, but that's not having an effect on releasing the new "style" with relatively the same benchmarks so consumers will still be fleeced out of spending money on a "new" product even if it's substantially the same and the "old" product
I'm just giving an example of my MSI (amd)5750 card I bought 2+ years ago vs 7750s, 7850s made today.. substantially the SAME benchmarks.. 128bit processors & all..