Qualcomm already confirmed that we'd see the Snapdragon 810 chipset in future Sony products, and the Xperia Z4 is likely the first to use it - that's why we assume that the device benchmarked now is the Z4. Of course, we might be wrong on this one.
The Geekbench webpage also suggests that the new Sony handset has 3 GB of RAM.
If we're to believe some recent rumors, Sony is readying two Xperia Z4 versions: one with a Quad HD (1440 x 2560 pixels) display, and another one with a 1080p screen. Obviously, the latter should offer longer battery life, being the logical choice for users who don't think a Quad HD screen offers significant benefits.
So, who's waiting for the Xperia Z4?
source: Geekbench via Blog of Mobile (translated)