A 270W Hawaii is tied to a 150W GTX 970, that is indeed some poor showing from AMD.
Ya those cards are from different generations. It's like sliding in a 780Ti in place of a 290X and claiming how it's inefficient junk against the 970/980.
Also, after-market 970 used 170-185W, not 150W. Not all Hawaii chips use 270W either.
HardOCP has XFX 390 system drawing just 43W more than MSI Gaming 970 system:
http://m.hardocp.com/article/2015/09/21/xfx_r9_390_double_dissipation_8gb_video_card_review/10#.Vxugmsj3bCQ
AnandTech shows an 80W difference between a 970 and a 390 rig.
http://www.anandtech.com/show/9784/the-amd-radeon-r9-380x-review/13
November 2014, Sapphire Tri-X 290 was on sale for $200 US with 3 free games:
http://slickdeals.net/e/7412008-sapphire-radeon-r9-290-tri-x-video-card-4gb-gddr5-3-games-199-99-ar-vco-td?src=SiteSearchV2Algo1
That means someone who jumped on such deals enjoyed a ~ 970 performance and has $130 extra to spend on a 650-660W Platinum or a 750-850W Gold Power Supply. All this time, outside of gaming the Hawaii card also made $.
It's even worse for the 980. PowerColor PCS+ 290X went as low as $254 November 2014, or a $300 savings over the 980'a $550 price at that time:
http://slickdeals.net/e/7448366-r9-290x-powercolor-pcs-axr9-290x-4gbd5-ppdhe-4gb-254-99-ar-visa-checkout-fs?src=SiteSearchV2_SearchBar
That means the 290X user has $300 extra set aside for Vega/Big Pascal or even the 1080.
So now you completely evaded how the entire Kepler line is getting annihilated by AMD, and also ignored the huge price disparity between after-market 290/290X cards when 970/980 came out to try to show that NV is doing well?
Btw, average US prices for electricity are $0.12 / kWh.
100W power difference X 4 hours a day X 365 days a year X $0.12 kWh = $17.52.
In Canada, in Ontario, the average rate is $0.085 / 1kWh. This would mean an annual cost difference of $12.41. Big deal. Modern AAA games have DLC that alone costs $30-60.
How much is the full price of Fallout 4 and the Witcher 3? Those 2 games alone = $240-250 US!
If I wanted to care about $12-18 in annual electricity costs, all I need to do is not buy just 1 AAA game at launch and wait until GreenManGaming or Steam has it on sale for 50% off.