Several UE4 passes has extremely high memory bandwidth on iphone

I’m profiling our game and find that the main memory bandwidth of several passes are extremely high on ipnoe x.
For example below is the counters captured by Xcode:

I only checked the BloomSetup pass, the input texture is the scene color texture with format RGBA16F and size 910 x 420. And the shader of this pass is very simple, it will down sample the scene color texture and output a 228x105 texture:

Assuming the game is run at 60 fps, so we have around 910 x 420 x 8 x 60 / (1000 x 1000) = 183MB per seconds, which is far less than the 9.38GiB/seconds bandwidth.

Can somebody kindly tell me what might cause the high memory bandwidth? Thanks in advance.

PS: when I run the game on iphone, it will warm the phone quickly and trigger thermal throttling so I think there is likely bandwidth issue and the data from the xcode gpu frame capture is plausible.

These passes do not have high memory bandwidth. I misread the data from xcode.