It needs a SD450 with it's far more efficient chipset built on the latest 14nm production process.
Already got them in stores over here. Grabbed one for a relative, its a better proposition than the equivalent samsung j3 with more ram, more memory but not as strong processor wise yet far better build quality. I kinda prefer it to the G5 as i hate the pointless bottom bezel on the g5 with the pseudo button.
Sounds like any other £50-£70 Chinese smartphone, oh wait...
I've checked in stores. Carphone Warehouse are selling it and I tried a display model. It was pretty nice, a very likable Nokia design and feel and the OS was likable too, great for the low price. Though only black is in store, blue and white need to be bought from Carphone online. EE and Amazon still haven't got it yet, only pre-orders.