The new Retina iMac is surprisingly power efficient.

[WilliamG]

These are just preliminary results from searching, but it looks like idling performance with the display on is improved from the 2012 and 2013 27" iMacs! Makes you wonder why the battery life wasn't better with the screen on with iPhone 6 Plus...


Power Consumption for 27-inch iMac (2012)
Mode
Off
Idle—Display off / on
100V 0.22W / 20.5W / 79.9W
115V 0.22W 20.6W / 79.8W
230V 0.22W / 20.9W / 78.9W

Power Consumption for 27-inch iMac (2013)
Mode 100V 115V
Off 0.24W 0.24W
Sleep 0.98W 0.94W
Idle—Display on 78.2W 79.1W
230V 0.24W 0.96W 77.0W

Power Consumption for 27-inch iMac with Retina 5K display (2014)
Mode
Off
Sleep
Idle—Display on
100V 0.26W / 1.18W / 70.4W
115V 0.24W / 1.11W / 70.4W
230V 0.28W / 1.16W / 69.5W

Results from here:

2012: http://www.apple.com/environment/reports/docs/imac_27inch_oct2012.pdf

2013: http://images.apple.com/environment/reports/docs/27inch_iMac_PER_oct2014.pdf

2014: http://images.apple.com/environment/reports/docs/27inch_iMacRetina5K_PER_oct2014.pdf

 

[colodane]

Thanks, William

Excellent (and somewhat surprising) info. I had a concern about power consumption with the higher resolution displays, but perhaps I had no reason to worry.

 

[Georgio]

Difficult to tell until people actually start using them, but I suspect we're going back to the 'egg-frier' iMacs pre 2012 with that GPU, especially the 295 flavour.