GFXBench 3.0: ALU, Alpha Blending, And Fillrate
ALU 1080p Off-Screen
Reminiscent of demoscene “progs” from the '90s, this ALU test measures pure shader compete performance by rendering a simple scene consisting of a complex shader and a single full-screen quad.
The great thing about GFXBench's low-level tests is that they more effectively isolate subsystem performance. In this case, we're shining the spotlight on shaders, without the impact of hobbled memory bandwidth. Thus, Qualcomm's Snapdragon 801 takes first place. Its 578 MHz Adreno 330 beats out the Galaxy Note 3’s 550 MHz by 11%. Both Snapdragon 800 -AB devices achieve very similar scores. The Nexus 5, with its Snapdragon 800 -AA, takes the second-to-last spot, while the iPhone 5s languishes in last place.
Alpha Blending Off-Screen
In these days of hardware-accelerated UIs, extensive particle systems, and render-to-texture effects, alpha blending performance is very important. In fact, it can mean the difference between a smooth user experience and a stuttering nightmare. This test renders semi-transparent quads using high-resolution, uncompressed textures to strain the GPU.
The trend repeats itself as the Xperia Z2’s Snapdragon 801 grasps the top spot by more than seven percent over Google's Nexus 5 and its Snapdragon 800. Strangely, the two Samsung devices equipped with the faster Snapdragon 800 -AB take third and fourth place. TouchWiz is probably to blame here, stealing precious alpha bandwidth to draw its overlays.
Fill Rate Off-Screen
This test measures texturing performance by rendering four layers of compressed textures simultaneously.
And there it is, folks: the Sony Xperia Z2 tablet has the highest fill rate score of the devices tested. No other benchmark so clearly illustrates the performance bump that Snapdragon 801 offers. The two Snapdragon 800 -AB-based devices take second and third place, tying almost exactly, per their comparable clock rates and SoCs.