Vulkan higher GPU bandwidth than OpenGLES

Hello everyone,

I'm testing the performance of Vulkan vs. OpenGLES using the samples provided here:

https://github.com/KhronosGroup/Vulkan-Samples

I modified the code to output an 8x8x8 cube of tori(donut) geometry. This seems to provide the GPU with some work and still run at 60fps.

I'm using a Huawei Mate 9 (Mali-G71) and am getting significantly higher GPU bandwidth (more than 20%) using Vulkan than with OpenGL ES, which I find puzzling. Both the Vulkan and OpenGL apps use direct set uniforms (push constants) and appear to have the same formats across all images/textures. They have the same formats when it comes to vertex attributes and the like.

Any ideas of where this extra bandwidth might be coming from? Is there a way to know whether or not Transaction Elimination is working on either Vulkan or OpenGLES?

Thanks!