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Slow performance with clouds

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I just updated my computer to a Core 2 Duo E8500 and a Radeon HD3850 512MB. I have 4GB RAM and am running Vista x64. Before the upgrade I had a E6420 and a Radeon X1950 Pro, everything else was the same.The upgrade brought some pretty nice performance improvements to FSX, except for one strange issue. Whenever there's a large number of clouds on screen (i.e. overcast) performance drops tremendously. Ultra-high settings on everything runs perfectly fine 30fps as long as I'm using "Fair Weather" or something like that. As soon as more clouds show up, performance degrades to about 5-15fps. It doesn't matter what else I do, even if I set everything else to minimal settings, I might gain a few frames back but it stays very slow.This did not happen before the upgrade! In fact, I got better performance in heavy weather with the old specs.I'm inclined to think this is to do with he graphics card, and not the CPU, as it still happens when the sim is paused, and if I change my view to look at the ground or something like that, where the (majority of the) clouds is no longer on screen, performance is back to normal.Any idea what could be causing this? Better yet, how do I fix it?

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hiI get similiar problems. I have maxed out the clouds draw distance and if you use any third party weather programs that create plenty of clouds then it does cause frame rates to drop. I have a Q6600 overclocked to 3ghz. Same as you, i get 25FPS anywhere (even Heathrow) with most settings maxed out. Put an overcast layer and it drops to 10FPS. I might look at using those lower resolution clouds that are more FPS happy. Not ideal but better than 10FPS.

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>I have maxed out the clouds draw>distance and if you use any third party weather programs that>create plenty of clouds then it does cause frame rates to>drop.Hi SanH,Thanks for your reply, but I'm afraid I'm seeing this issue with default settings and built-in weather (e.g. thunderstorm or even real world weather on many occasions). Even if I reduce cloud cover to minimum it still happens (although less since there's less clouds, but anything more than fair weather will cause trouble).Again, this issue didn't happen on the same settings with a slower CPU and GPU, it's only after this update that I'm seeing this bizarre behaviour.

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For me clouds have the biggest impact. A thunderstorm, for example, is the worst. I can be out in the middle of nowhere and I get 10-15 FPS. My system is E6850 at 3.4G, ATI HD2900 pro (512 mb), 2G RAM.I tried lower res clouds and that had no difference. Also, Active Sky X made it worse.I think its normal. I did try playing around a bit with the "CloudArtFiles.xml" file. I replaced some of high impact cloud types with ones that had a lower impact.

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I have it too and I see the common theme already - ATI Radeon HD cards. I'm running FSX on an iMac (windows xp - boot camp), runs great until I get anything resembling an overcast, then it just tanks down to 10-12 fps. My only solution is to use the simple clouds it seems. Perhaps we should all submit tickets to ATI, as it seems its a driver issue.

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Hi all,I just ugrade to an E8500 (now o'clocked to 3.63Ghz) but I have an Nvidia 8800GTX graphic card. I have no problem with clouds from a few wisps to a screenful of cumulus. The upgrade to the E8500 from an AMD 6000 was the best move I ever made with respect to FSX performance. I am very pleased with the extra performace I am getting with FSX. So its not the CPU that's giving cloud problems and the finger of suspicion must next point to the graphics sub system.John

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I'd just like to know where you got an E8500 - haven't been able to find any here in the US...

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If can add some confusion to the mix, I'm running a spanking-new Sapphire ATI HD3870 (which I am ENORMOUSLY pleased, overjoyed and tickled with, I must say) and the cloud impact is now absolutely minimal - FAR far far far better than wth my old 1650 PRO 512 MB ATI card. On a non-O/C E6750 CPU. So, minimal bottlenecks now.But also, with FEX too (and prior to the new vid card) which helps with them-thar clouds and stuff anyways and looks all fantastical n'such. But the HD3870 just cranks through them clouds an mist and fog much better.

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Have you also noticed that in spot view from the rear, water and snow spray have the same hit? For me these are almost worse - I had to remove the effect. I also think its the ATI card - I have HD2900 Pro. Can figure what it is. Same problem for all ATI drivers and clean install.

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Sorry but the theory that poor cloud performance is an ATI thing doesn't play out in my case, in fact it's the exact opposite. I just upgraded from a x800xt to a 8800GT and was amazed to find that clouds can eat this board alive. I didn't have near the problems with the old board - wierd. In fact, I can gain one slider (to very dense autogen) since switching over, but frames are better overall, especially on the ground. I had read that Nvidia applies AA/AF to clouds which hinders performance, while Ati doesn't, but don't know if this is the root of the issue.Regards, Kendall#1: E6750@3.2GHZ/Coolermaster HyperTX2 Gigabyte P35-DS3L 4GB Crucial Ballistix Tracers PC6400 Seagate 250GB 7200.10 SATA2 Gigabyte X800XT -Cat 6.12's CH Yoke/Pedals/Saitek Throttle Dual Monitor: Dell 2405/1905 #2: Dell 8400 3.2 H.T. 3GB PC4200 Diamond Xtreme/Logitech X-530's

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>If can add some confusion to the mix, I'm running a>spanking-new Sapphire ATI HD3870 (which I am ENORMOUSLY>pleased, overjoyed and tickled with, I must say) and the cloud>impact is now absolutely minimal - FAR far far far better than>wth my old 1650 PRO 512 MB ATI card. >>On a non-O/C E6750 CPU. So, minimal bottlenecks now.>>But also, with FEX too (and prior to the new vid card) which>helps with them-thar clouds and stuff anyways and looks all>fantastical n'such. But the HD3870 just cranks through them>clouds an mist and fog much better.How many MB? I have a Radeon HD 2600 XT (512 MB) and I have the same cloud problem as everyone else with an ATI. MAYBE THEY SHOULD PUT OUT NEW DRIVERS... although I doubt they're reading this.

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512MB on the HD3870. Seriously, not seeing a huge framerate impact - but - I did see it with my 1650.Same effect in IL2 and other flight sims as well...much better now.

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>Sorry but the theory that poor cloud performance is an ATI>thing doesn't play out in my case, in fact it's the exact>opposite. I just upgraded from a x800xt to a 8800GT and was>amazed to find that clouds can eat this board alive. I didn't>have near the problems with the old board - wierd. In fact, I>can gain one slider (to very dense autogen) since switching>over, but frames are better overall, especially on the ground.> I had read that Nvidia applies AA/AF to clouds which hinders>performance, while Ati doesn't, but don't know if this is the>root of the issue.>>Regards, Kendall>>#1: E6750@3.2GHZ/Coolermaster HyperTX2 > Gigabyte P35-DS3L > 4GB Crucial Ballistix Tracers PC6400 > Seagate 250GB 7200.10 SATA2> Gigabyte X800XT -Cat 6.12's> CH Yoke/Pedals/Saitek Throttle > Dual Monitor: Dell 2405/1905 >>#2: Dell 8400 3.2 H.T.> 3GB PC4200 > Diamond Xtreme/Logitech X-530'sI also have a 8800GT and no problems with clouds here. What driver are you using?

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I, too, am not in favor of ATI being the culprit. I have a GS8600GT 256MB (I know, not high-end...) and I also see a significant impact of clouds and vapor/spray. Other specs are C2D E6850 @ 3.8GHz, 3GB PC6400 RAM.

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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

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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

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

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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.

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>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.

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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.).

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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.

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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?

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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?

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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.

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