In theory it should be less. LCD's start with a white light, then attenuate it through red, green and blue filters. OLED's don't lose light to generate colour,

In theory it should be less. LCD's start with a white light, then attenuate it through red, green and blue filters. OLED's don't lose light to generate colour, they produce red, green and blue light directly, so all other factors being equal should have a significantly higher potential efficiency.