Slow performance with clouds

[albar965 1,040]

On a clear day in sparse scenery I can get up to 100 FPS. Average is somewhere around 40. Clouds can lower FPS down to 20 which is really going on my nerves. I already limited the number of cloud decks to 2 in ASX.It is for sure linked to heavy AA modes like 4S or 8S. The impact is not that heavy if I use the FSX built in AA (whatever that is).Fortunately there is a driver bug I can use there *:-*. If I go to full screen and back the AA goes back to FSX standard modes and performance is good again (with reduced graphics quality).Alex

[Glynn 405]

HelloI had a succession of ATI cards 9600, 9800XT, X850XT, X1950XTI always has fps when in clouds but fps fine when in clear skyChanged to an Nvidia 8800GTS 320mb and fps does not drop no matter how many clouds I encounter.I think it may be an ATI issue

[bobbyjack 61]

Well, Clouds don't bother my 8800gt at all, but AI can sure do me in.BobE6750,2GB 667,8800gt,stupid 17 inch crt

[PhilTaylor 45]

Clouds, and any effect that requires transparency, require heavy memory bandwidth because these are require a RMW memory operation, eg read, modify, write. That translates into something like, with the "next cloud object/texture:1)read the backbuffer at each pixel location, 2)examine the depth/transparency info that already exists against the new info for the cloud/texture at hand at each pixel location, 3)modify the memory value based on the examination for each pixel location, 4)write it back out for each pixel location.Alpha is expensive. Period.8600s have significantly less memory bandwidth, that is why 8800 users are not seeing the same costs.see http://blogs.msdn.com/ptaylor/archive/2008...d-consumer.aspxfor more details on evaluating the feature set between family variants.

[Alvega 2,119]

>Well, Clouds don't bother my 8800gt at all, but AI can sure>do me in.>>Bob>>E6750,2GB 667,8800gt,stupid 17 inch crtI agree with you here, AI is the main FPS eater for me also. Specially when we use MyTrafficX (for me the best), which adds much more AI planes than any other AI. But i can live with a couple less FPS, can't live without MTX though.

[Valcor 9]

My system:6750 OC'd to 3.5gHZ4gigs corsair RAM8800 UltraI run with autogena and complexity sliders one setting from full, cloud distance at 70mi and AI at 25% with MyTraffic and my frames stay between 25 and the locked 30 in almost every situation....except;Overcast skies (This is without ASX or addon weather). My frames stay pinned at 30 even with many large cumulus clouds all around me, thunderstorms, etc. However, if I set the weather theme to "Gray and Rainy", and enter the overcast layer, my FPS takes a dive to around 15. This drop takes place even in remote areas. For some reason, its only being in the scud type cloud layer that really hurts my frames. No other cloud structure seems to impact FPS.I have experimented with various AA and ASF settings (including off) and nothing changes it. I am hoping that REX will help this problem with it's different cloud texture options (DXT, etc.).

[Valcor 9]

After reading posts here and seeing Nvidia users with no problems with clouds I did some further testing.Strangely, if I put the FPS slider on Unlimited, I gain about 5 FPS in the overcast conditions I talked about above. The puts me at about 20 FPS in the worst weather, which I'm very happy with.

[Guest JoeInCT]

Just built a new PC with a Q6700, 4GB RAM, Vista Ultimate, and NVIDIA 8800GTX and I am seeing the same thing. I get smoking frame rates (30-40 fps), even with the sliders up at major airports such as KATL or KORD. Throw in a few clouds and BOOM, down to 9 fps. Anyone?

[Guest JoeInCT]

FYI, within FSX I have Ansio selected but not AA, and 8AA and App Controlled Ansio in my NVIDIA control panel.I suspect the problem has something to do with my 8800GTX doing AA when rendering the clouds -- which is a hog and it shouldn't be doing in the first place.Anyone?

[Guest JoeInCT]

I did a little test... I created a solid overcast layer up to 20,000 ft and leveled off at 8,000. NOTHING BUT WHITE. I changed only the AA in my NVIDIA control panel from 8AA to 4AA and now I am getting an average 30 fps with an occassional 60 fps. If FSX is truely optimized, why would FSX use anti aliasing when drawing clouds AT ALL? I don't get it. I suspect it will be blamed on NVIDIA. But then again, the unseen terrain is probably still being rendered since I theoretically COULD catch a glimps of the ground through the cloud. If the terrain IS being drawn, the line algorythm (and thus AA) is still being used -- and when added to the alpha needed for the clouds, it could dog the system even though I am seeing nothing but white. Perhaps I answered my own question.-----I'll get her down. And down safe.

[GHarrall 494]

I wonder if the in game FSX AA doesn't apply AA to clouds?In this case it may be better setting AA to 'on' in FSX and changing the nvidia / nhancer setting to 'enhance application' I might give this a go when I get home tonight......

[GHarrall 494]

Phil, Is there any way to tell FSX or the GPU driver to NOT apply AA to alpha textures?Is this already a feature?Thanks,

[Guest JoeInCT]

>Phil, >>Is there any way to tell FSX or the GPU driver to NOT apply AA>to alpha textures?>>Is this already a feature?>>Thanks,I'm not convinced the problem relates to FSX or video card using AA when DRAWING THE CLOUDS exclusively. Aren't they just bit maps anyway? Would rendering the clouds require the use of AA? In my college graphics class a few years back, we used AA only as part of a line drawing algorythm.I am thinking the inefficiency has got to be related to the drawing of the terrain (which I would think would have to use line drawing algorythm and thus AA) IN CONJUNCTION WITH the ALPHA stuff that needs to happen to blend the terrain (ground, roads) with the (white/gray) textures of the clouds. Even if the view out the window is full white, I imagine it is still blending the terrain with the clouds. We know from the problems with Autogen that Alpha is computing intensive. But even so, the clouds should not have that level of performance hit. I gotta believe there is a bug somewhere - most likely in the video driver.Still, why in the heck is a few clouds bringing my quad processor machine (Q6700) with a NVIDIA 8800 GTX to its knees when I get killer frame rates otherwise???? There has got to be a configuration (other than lowering the graphics card AA) that eliminates this ineffeciency (problem) without sacrificing image quality. Or perhaps the next video driver upgrade will fix it? I dunno.I just hope whoever might know the solution for this didn't have fish for dinner.

[Guest thx1137]

Hmmm. I have an 8800GT too but FPS never gets below 20 in overcast or thunderstorms. I used to have poor performance but I think, not sure mind you, that running FEX has help my cloudy FSX performance. Until I got FEX I was only flying on cloudless days so maybe I did something before FEX...Steven.

[ginopatrassi 7]

Ok, I have a 8800GT with a E8400 3.0ghz, 4GB of RAM, Xp 32bit. I use Active sky X and FEX HD....I think that it depends on the theme of cloudsSometimes i have strong fps decrease with overcast... something like 8-9 fps. In other conditions with other themes installed 15-18-25.It depends....Fsx is very delicate, a little change can result in a strong performance change!AA of course has something to deal with it!Yesterday i flow with dramatic 8 fps. Today 19-20 but i did not change anything!!!