[SOLVED]GPU bandwidth?

Hello!

There is a lot of talk about the limitation of the switch, whenever a game is out. Although people are quite pleased with the series of "impossible" port, there is always comparison about where the cut had to be made and which weak point drag performance down, that is the GPU or the CPU. With the advent of overclocking on the console, it settle that discussion a bit, as people can overclock one or the other separately.

However, with the advent of the remake of zelda link awakening, there was a lots of puzzlement as frame drop persisted inconsistently relative to overclocking. The problem assuredly is probably bandwidth, people reasoned.

AND I have realized I didn't fully understand how GPU bandwidth actually factor in a game. I mean how do we compute the bandwidth budget of a target platform? For example the switch is roughly +20gb/s that is +300mb at 60fps, a raw 1080p is roughly 8mb, I guess texture read factor in that too, but what does look a typical GPU bandwidth budget?

 

Okay I finally found useful stuff that build intuition, since I'm targeting weak phone, it's important data to me for evaluating order of magnitude:
https://community.arm.com/developer...nomenal-cosmic-powers-itty-bitty-living-space
http://twvideo01.ubm-us.net/o1/vault/GDC2014/Presentations/Martin_Sam_The_Revolution_in.pdf

https://developer.samsung.com/game/gpu-framebuffer

Similar budgeting evaluation "intuition"
https://community.arm.com/developer...ts/better-living-through-appropriate-geometry
https://community.arm.com/developer...ommentId=10358576-0a28-44a1-b8c3-4afc8ad14347

https://developer.arm.com/tools-and...amline-to-optimize-applications-for-mali-gpus

In the end real number is down to architecture, but still you would be a off by factor less than order of magnitude. Some of these number really put some stuff in perspective regarding choice of visual, if only I could find some number on key bandwidth bus of the mali 400

 

Budgeting bandwidth as performance optimisation is a bit tricky, you need to test. By this I mean compression formats, screen resolution, post effects, etc, all of these consume wildly different bandwidth. Even varying mip levels will produce different results.

I mean you probably don't even know what format it'll end up on the target device sometimes. You will have to test but can make some educated guesses to save bandwidth.