I personally see 1.7Ghz being the clock speed couple along with 2GB of RAM (that the many leaks make it a good bet), and a 6 core PowerVR series 6x GPU.
Whatever it is, I hope it's significantly faster than the iPhone 6/6 Plus. It's a much larger device, and as such - should have access to a great deal more power than a mere phone.
Why not? The Air was barely a scratch higher than the 5S and the Air 2 is rumoured to have more ram and the same resolution as the Air so doesn't need a higher clock. I expect it to be the same as the plus.
Why not? The Air was barely a scratch higher than the 5S and the Air 2 is rumoured to have more ram and the same resolution as the Air so doesn't need a higher clock. I expect it to be the same as the plus.