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Cloud Shadows/Water 2.x Mid - Potential for performance optimization?

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A question for Steve and the thread title basically says it all.


I do really like the cloud shadow add-on for DX10, but having to have the water settings at 2.x mid does come with a bit of a performance hit for both of my systems*, especially since I've only ever had water at 2.x Low before.

In high demand situations, e.g. around busy airspace and complex scenery (default JFK, looking downtown), the second shader pass invoked with 2.x Mid and (probably) all the associated anti-aliasing (4x in FSX plus 2 x SGSSAA in Inspector for the desktop PC) comes with a 3 to 4 FPS penalty (compared to water at 2.x Low) . While this may not sound like much, every frame counts when the surroundings get demanding. I've essentially had to drop my FPS limit from 30 to 20 to retain smoothness.

For optimizations, I'm thinking along the lines of removing cloud and airplane reflections on water from the associated shader or not allowing anti-aliasing or other texture filtering for the reflected items (similar to what is done for the clouds themselves in the main DX10 shader). The former wouldn't be an issue for me since I really just want the cloud shadows and nothing else.

So is further performance optimization of the water/cloud shadow shader possible?


(Drivers or software settings can be ruled out as causes for the performance impact. I maintain my systems well.)


*i5 4670k w/ 4.2 GHz Turbo, 8 GB 2400 MHz RAM, GTX1060 6 GB; i7 6700HQ w/ 3.1 GHz Turbo, 8 GB 2133 MHz RAM, GTX960M 2 GB

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Sorry but I don't believe that there is anything that can be done.  In most cases the frame rate in the scenarios you describe are cpu bound.  The only exception is if your gpu is too weak for the aa the that you have selected.

To test this turn off all aa and see what happens to your frame rate in the scenarios described.   If it goes up then you need to lower aa or buy a better gpu.  If it stays the same then the limit is cpu.  

If the limit is cpu then changing things in the shader wil I am afraid have no impact as the cpu cost has already occurred,.

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I've just spent way too long playing with different AA modes and up until 8 x AA (set in the Fixer), I see no definite difference in performance (that's where the second shader pass starts to hurt, I guess). Same with anisotropic filtering on and off.

So it's definitely the CPU. Would love to see what a difference 4.5 GHz or a newer chip make for the desktop PC, but the chip is clocked out and I'm in no position to upgrade at the moment.


Anyway, thanks for the input. Too bad there's nothing that can be done.

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