The  are already some of the most luxurious convertibles you can buy, with a gorgeous, watchband-like 360-degree hinge. Now Lenovo's adding yet more premium features. Announced Thursday at IFA in Berlin, the new flagship Lenovo Yoga 920 laptop will support , which promise up to 40 percent more power even in slender notebooks. This is a sea change for portable PCs, and the Yoga 920 is riding the wave.