Fastest uniform read vs. fastest texture read

1

Greetings,

on PowerVR 6, I assume the fastest way to read a uniform is if it is stored in one of the sh registers, right?

Now, what is the fastest texture read possible? Does PowerVR6 cache texture reads in some way? How does it best-case perform compared to the uniform scenario above?

Regards

2

Hi,

yes and the compiler will do its best to store uniforms in there.

I think the fastest you can go is a single texelFetch
yes it does have multiple caches to help with bandwidth usage. The amount will depend on the exact GPU configuration.

I think the uniforms will be loaded once per program, whereas the texture sample may or may not stay in cache depending on what other data needs to be cached. Obviously the less data needs to be cached the higher the chance of it being loaded only once.

bests,
Marton

3

Ok, and is this single texelFetch faster than a uniform read from a register? My assumption would be that registers are fastest.

4

registers are indeed the fastest :slight_smile: