This test is designed to measure how many frames are processed by the GPU in a set period of time allowing GFXBench to reveal the fps frame rate for the unit being tested. The Sony Xperia Z4 (E6553) employs the Adreno 430 GPU according to GFXBench. The handset scored high by running 1115 frames at a rate of 18 fps. The LG G4 (F500x, H815) has the Adreno 418 GPU inside and ran 348 frames during the test, which worked out to a frame rate of 5.6 fps.
The data also pretty much confirms that the Sony Xperia Z4 will have the octa-core Snapdragon 810 SoC inside, while the LG G4 will be driven by the hexa-core Snapdragon 808.
Thanks for the tip!