That's not what the french quote is saying. They said that the GR6500 is the same configuration (except the RT block of course) that the PVR found in the Iphone6, but the clock speed is doubled.
That can't be right: it says if I'm not mistaken that the GR6500 clocks at 600MHz. The GX6450 in the Apple A8 should clock somewhere in the 500+MHz region.