I get reasonable frame rates most of the time, but whenever there are many clouds in view, my frame rates drop considerably (as much as 10 fps). I have the density on medium and draw distance on minimum, but I still get a sever impact on the fps. Is there anything in particular I can do (preferably short of changing the settings to "simple clouds" instead of "detailed clouds") the get better fps when flying near clouds?

Thanks
boeing247

Those FSX clouds sadly are fps hogs when using any kind of super-sampling AA. That's by design and even the strongest cards struggle there, more or less.
You can test this when altering the AA mode and then starting FSX with a cloudy setup. The impact should be less severe then.
As a downside, the image quality then goes down a bit too, but this depends on personal preferences of course.

When using an ATI card, the shader 3.0 mod can help you with cloud performance. Just google it, this should lead the way to some Avsim resource where you can download it.

I can't find the shader 3.0 mod on avsim, and non of the other links on other sites I've tried have worked. Where is the best place to download it?

Here's the thread, but you have to use the links in Bojote's signature to get the current shader version. The one in the first post doesn't work anymore.
http://forum.avsim.net/topic/283701-bojotes-shader-30-mod-for-fsx/

Thanks! I'll test out FSX with the shader soon--it sounds like it should work.

The shader did not help. In fact, it made things worse. My water textures are stagnant (no animation), the reflection is ridiculously bright, and when I zoom out on top-down view, the world appears a a large, bright-blue circle (though that last one is listed as a known problem).

Have you used this, and if so, have you seen a performance increase?

That shader 3.0 thingy only helps ATI cards in the clouds, the Nvidia guys won't see any fps improvements.
The 'zoom out haze' is a known downside there, but all water related things can be tuned when sticking to the included readme.
You are just seeing Bojote's preset there, which can be altered.

But I would recommend reverting back if the optics didn't improve for you. As said, the FSX clouds come with the general downside of causing a large fps impact when using any type of super-sampling anti-aliasing. So I would, for testing, recommend to go to a normal AA mode and see if that help the fps. It should, be design.
Use the driver menu or tools like Nvidia Inspector there and avoid any SS (which stands for super sampling) in the mode descriptions.
Also, any transparency AA (which uses super sampling) will put more load on the card, so maybe leave it off for testing.
You can later apply some more AA until reaching a point where the image quality doesn't improve much more while the fps stay friendly. This will always be a tradeoff situation in FSX.

The modes you can use (with clouds) depend on your card. The smaller ones struggle some more while you gain some headroom on the top models. But even a GTX580 can easily be spoiled with the combination of SSAA and dense clouds, don't get that wrong. The way that FSX draws clouds is the culprit there.

Actually, I have an ATI card, a 1GB AMD Radeon HD 6450. I have the AA settings as "Use application settings," which I figured would be lowest.

With that card, you are into two troubled waters (for FSX) at the same time. ATIs may give you less fps than the Nvidia things and you are also using a low bandwith/low GPU model.

If you have already switched the shaders (which should help that card), stayed low on the AA side (app. controlled is low, you are right) and also have the cloud density and draw distance in FSX turned down, there won't be much to improve then.  :-/

If you still struggle, maybe put a nowadays cheap GTX460 1GB on your wishlist. This will also improve other games as it's a relatively capable performance card. Cards like HD6870 are also good, if you want to stay at the AMD/ATI side.

I have turned down density and draw distance, but my fps in cloudy areas is still less than desirable. Any thoughts as to why the shader mod might not be helping?

To enable the shaders, one entry in the fsx.cfg is needed and you also have to force a rebuild then. Those two steps are vital, others may be too.

From the readme. You can either use the installer or do all the steps listed here.

Quote:

DETAILED INSTALLER ACTIONS ========================== The auto-installer will perform the following actions AUTOMATICALLY:      AUTOMATIC INSTALLATION      1) Copy a temporary folder with the new Shaders to your FSX root directory with the name: ShadersHLSL_SM3_BOJOTE      2) Copy a temporary WaterConstants.Xml file to your FSX root directory with the name: waterconstants_sm3_bojote.xml      3) Copy this readme file to your FSX root directory 'Shader3 Mod for FSX' subdirectory with the name: readme.txt      4) Automatic rename of your original ShadersHLSL folder to ShadersHLSL_ORIGINAL      5) Automatic rename of your original WaterConstants.Xml file to WaterConstants.Xml.BAK      6) Automatic rename of the temporary folder ShadersHLSL_SM3_BOJOTE to ShadersHLSL      7) Automatic rename of the temporary waterconstants_sm3_bojote.xml file to WaterConstants.Xml      8) A 'Shader3 Mod for FSX' subdirectory is created under your FSX Root with 'optional' goodies, readme files and misc information.      9) DX9 & DX10 cached shaders are automatically DELETED. This folders are located here:         %LocalAppData%\Microsoft\FSX\Shaders and %LocalAppData%\Microsoft\FSX\Shaders10 this is a completely SAFE operation.      10) Once all the above steps are complete, the following changes will be performed on your fsx.cfg file:            [GRAPHICS] => ALLOW_SHADER_30=1            [GRAPHICS] => SHADER_CACHE_PRIMED_10 is REMOVED            [GRAPHICS] => SHADER_CACHE_PRIMED is REMOVED            [GRAPHICS] => SHADER_CACHE_VERSION is REMOVED            [MAIN] => PerfBucket is REMOVED            [MAIN] => ProcSpeed is REMOVED            ALL the removed values (except SHADER_CACHE_VERSION) will be written again by FSX to your fsx.cfg in the next restart so this            changes are 'minor' and completely reverted by doing an uninstall.      AUTOMATIC REMOVAL      1) Automatic Delete of current ShadersHLSL      2) Automatic Delete of curent WaterConstants.Xml      3) Automaic rename of backup (original) ShadersHLSL_ORIGINAL folder to ShadersHLSL      4) Automatic rename of backup (original) WaterConstants.Xml.BAK to WaterConstants.Xml      5) The changes made by the installer to your fsx.cfg ARE reverted. The ALLOW_SHADER_30 line will be removed.      6) Complete removal of the 'Shader3 Mod for FSX' folder that we created on your FSX root directory      THE REASON WE PROVIDE THIS DETAILED LOG IS FOR YOU TO KNOW 'EXACTLY' WHAT THE INSTALLER IS DOING. The installer is NOT necessary to install

I'd recommend using a draw distance at the very lowest setting and a medium cloud density with your card.
Please don't get that wrong, but your card is a low-end model by all means. It may have enough VRAM for FSX, but the rest is more of a 'too low' than 'enough'.

Okay, I didn't force a rebuild. How do you do that? (Sorry for all the questions, I just want to be sure I'm doing everything correctly so I don't screw anything up  ;))

When going manually, follow the blue marked step while FSX is not running.
On the next start, he will recompile his shaders then. You will see a progress bar there, to be sure it happens.
As the description above is a bit cryptic, just use C:\Users\YOUR USERNAME\AppData\Local\Microsoft\FSX and look for all Shaders folders there. Delete or move them and then start FSX.

The installer should already have taken care of that, so maybe you actually did get new shaders, but it did not help much on your card.
I hope I'm wrong though.

Nope. The shaders were removed. The reappeared when I uninstalled the mod and opened FSX.

That's normal. You or the installer deletes them, you restart FSX, he compiles new ones and the folders are there again. But their contents then differ. That new stuff are your new shaders then.
As said, if those new shaders and the low settings didn't help, there's no holy grail left anymore. Maybe you can borrow a more powerful card from friend to check the influence there. The mentioned GTX460 or a HD6870 might help a lot.

FSX first of all is CPU limited, but those cloud thingies actually are more bound to the graphic card and her bandwith and overall GPU performance. I know that the advertising of your card might explain some game capabilities, but they are very, very limited there.
So if your CPU isn't too weak, maybe a card update helps.

Maybe you can install some lower resolution clouds or get rid of the HD ones (if e. g. REX has installed those at your system). This should help a bit.
I'd search the Avsim library or so or would use REX with a setting of low resolution clouds to test this.

If you reduce the overall texture resolution with the slider in FSX, you will also free up some space, but lose quite some image quality. You can test this though.
One notch below very high at 'Global Texture Resolution' or even one step further down does this. find that slider at the Graphics setting page in the FSX settings.

Is the HD 6870 compatible with the Dell XPS 8300?

I don't know that Dell system.
But if it has a free PCI-E slot (which it should have when removing your current card) and can deliver the case cooling and also power needs of the new card, it should work.

Maybe some hardware expert from your friends can help you there, checking this highlighted stuff before buying.
The more powerful cards produce a lot of heat and need much more power than your current card, so a closer look is recommended. If Dell e. g. used a small power supply, you won't get a stable system there.
Otherwise, a shop has to help, but will need money for this.

I think that AMD recommends a 500W PSU for that card and I don't know if Dell included such a thing. The case cooling also needs some 'flow' to allow a safe operation which also covers the noise produced.
They usually recommend too high PSU values there, to be on the safe side. But let those decisions be up to a guy with some hardware knowledge, when looking at your system more closely.

But maybe try those replacement clouds (and slider settings) I spoke of. They are cheap or come at no costs and might help a bit, before buying new hardware.  :)

I saw that there is a replacement cloud texture package (50% reduction in resolution, which makes them fuzzier, but clouds are by nature fuzzy) by Mike Kelly. However, I can't find where to download it. Does anybody have this package/know where to download it?

Well, if anybody does know the link, notify me, but in the meantime, I've found this: http://simviation.com/1/search?submit=1&keywords=oscar+cloud&x=0&y=0 It is meant to provide less gpu-intensive and more realistic-looking clouds. However, it does come with high-res clouds if you have a good graphics card.

I'm now getting 20FPS and 15FPS in metropolitan areas--all sliders are high or max with the exception of clouds. (Personally, I think those are good frame rates. Some people demand 60 FPS, but I don't notice any major difference after 15-17FPS).

If those 15-20 fps come in smoothly, that's a nice improvement. Glad to read this.