P3D Water = Max GPU Usage?

[nudata 10]

Messing around in Slew mode, on my system, My GPU usage is max at 99% over the Pacific Ocean far from land. If I place the aircraft over ORBX inland away from water the GPU usage drops to 50%. FPS are around 150 over water and 80 over land. Water reflection slider was at min. Sliding it to max no differences in either case. Also used fixed weather with no clouds, noon in the summer season. Are those pretty waves heating up the video card?

[Kosta 122]

This is something I noticed in a test of mine: same REX-E textures, and I get 141fps in FSX over water only at dusk, and 82fps only in P3D, same water settings to reflect clouds, but not scenery.

[ChaoticBeauty 6,692]

Maybe it has something to do with bathymetry, even when it's turned off?

[TheGrunt 44]

It may well be that it is simply because of the differences in their respective shader codes. After all, graphichs engines are different in that area and as such performance differences are more than likely.

 

Bathymetry may of course play part in it and water algortihms were changed because of the added bathymetry feature. Dunno.

[ChaoticBeauty 6,692]

In the Prepar3D features page I'm reading "dynamic water". What is this, and did it exist in FSX?

[Kosta 122]

I am stumbled a bit upon one thing: if P3D offers much better water, why doesn't it look better? I mean, it does in the original state, but when the same REX-E textures are installed, not any more, then it's all the same.

 

Could it be that those REX-E textures must be made for Shader3, and are made for Shader2? I don't know much about the background of this stuff, but all I can say that with Sparkling installed, I cannot detect ANY visual difference between FSX and P3D in terms of water quality, except maybe just a little bit more clarity in cloud reflections, but that's about it. But terminally lower performance.

 

 

EDIT:

Aaaaaand btw, I just tested a dusk water situation loaded with unlimited FPS, as aforementioned same textures, and it shooted up my GTX580 right up to 96% usage.

[nudata 10]

Just for the record - RE: Original msg

 

Video card nVidia GTX 550TI 1gb mem 360.2 driver, i2550 3.4ghz,. 8gb memory

 

I need to turn off REX stuff.

 

Isn't most shader computation done on the card? Probably the culprit. Is there a way to turn off shader-3?

[TheGrunt 44]

Isn't most shader computation done on the card? Probably the culprit. Is there a way to turn off shader-2?

You probably mean Shafder V3, swhich P3D has?

 

In short: no.

 

Shaders aren't just some driver level postprocessing such as AA or AF, but they are code which is integral part of rendering: calculations for object colours, effects (Bump mapping etc.) and object coordinates on 2D screen are done by shaders. There is no reason to code shader for two different versions as there is really no reason to use V2 over V3 (unless you have some sort of vintage Graphichs card with just V2 support). V3 is in no way slower per se with same calculations, but something has been obviously changed for the P3D shader code for water as it is clearly more heavy. I have no clue what it is, but Lockheed boys probably would have an immediate ansewer for this.

[nudata 10]

Turned off REX and all P3D sliders, etc. in P3D. Still 99% GPU over water. For me not a big deal now but as more visual features accumulate it may not be good. 200 FPS over the Pacific looked good.

[jzimmermann 238]

In the Prepar3D features page I'm reading "dynamic water". What is this, and did it exist in FSX?

 

It means you can take a swim if you want to...explore the depths of the Indian Ocean from the privacy of your...P3D rig :lol:

[Cleric812 0]

I had a similar issue with the water using up 99% GPU but only if I used a 32-bit oceanheightfield texture. This resulted in a lots of stutters. When I used a regular DXT1 texture the problem went away and GPU usage dropped to 40% This was in FSX though, I haven't tested this in Prepar3D yet.