First, let me start off by saying I play flight simulators since they first apeared, back in the Spectrum 48k era.
I'm passionate about Flight Sims, and the only two games I have currently instaled on my PC are MSFS 2002 Pro and CFS 3.

This is cause I have PS2 console and that takes care of my basic action game needs.

For MSFS 2002 I didn't had any doubts. It's the only big civil aircraft simulation out there.

But for CFS 3 I admit I did some thinking. I have a Pentium IV, 1.8 Ghz. I'm not really shure of witch video card I have but it's at least 32 MB.(I have a portable computer and I didn't install it myself).
I simply loved CFS 2 and 1 . I imersed completely in the WWII air war and I considered them the best Combat Flight Sims I ever played.

MSFS2002 runs smoothly and perfectly on max detail.

I had forgoten about the real pain it is to tweak you PC to the game but, yes, you must do it. That's something I like on the PS2. Just stick the game CD and play.

I recomend the DirectX 9. patch and creating a Swap. I found a usefull article on this with 10 tips on how to speed up the game. I'm shure this was already posted by others before but I noticed there is alot of complaining about the game speed.

I'm shure Microsoft could have done better, like it did in Flight Simulator 2002.
It's true that CFS 3 has alot of AI, thousands of mouving objects etc.. but the ideal future I see for CFS4 is a mix between the two, a perfect blending.
The game is very demanding. If you have a good piece of hardware, you will like it. If you dont have a fast machine, you will hate it.

We could all discuss why Microsoft launches products that are clearly over demanding in terms of systems capacities that are available to the average person, but when evaluating a game, we should all focus on the game itself, not on it's performance needs.
The good thing about PS2 or other consoles is that the same games will run the same everywhere, so reviews are comparable.

I will try to stick to the game details.

The thing I like the most is realism and tough chalenges. That's why ALL modern times based flight sims are now un-apealing to me. Except the excelent IL-2 series or others that are based in eras where being a combat pilot was actually risky enough to make a game out of it . And you have to go back to the 60's at least, or mid 70's tops! Todays technology supremacy of the 'good guys' is just to big, and when games are based on real todays wars like F-15 Strike Eagle II was based on Gulf War, it simply wasnt realistic, because if it was, it would be too easy.

But in WWII, if you were a combat pilot, you had to have cojones. If you read Saint Exupery descriptions of how the life of a pilot was, you will get the idea. No sleep, tons of casualties, particulary in the rookies.
This makes the perfect context for a game. You will survive if you are good, and you will die if you are lousy or unexperienced (or unlucky).

If some company wants to make a modern fighter flight sim apealing to people like me, it will have to do something like Flight Simulator 2002 + Some Action.
I would love to play a game were I would pilot one of those B2, take off from England, drop 5000lbs of bombs on an Iraqui Bomb, and quietly land back  

Tip# 4: Shut down any background applications and tools
Every computer system has limited resources, and games run best if they don't have to compete for those resources. Making sure that background tasks aren't eating up those resources will make any game run better.
Press ALT+TAB to cycle through any open programs and close them all down. Look at the system tray in the corner of the taskbar for programs that run in the background. You may have some device manager associated with your joystick or video card that you want to allow to remain so that you can use custom configurations, but aside from those, you can safely close the rest by right-clicking them and selecting Exit or Disable.
If you're a power user, you can call up the Task Manager, switch to the Processes tab, and terminate any processes that aren't absolutely necessary. If you don't know how to call up the Task Manager, this is a step you should probably avoid.
Anything you shut down will start back up when you reboot, so mistakes are easy to correct, but you must remember to go through this process again the next time you play.

For more details on preparing your PC for a clean shutdown and reboot, follow the below link to the "Microsoft Product Support Knowledge Base for Combat Flight Simulator 3.
http://support.microsoft.com/default.aspx?scid=KB;EN-US;331796

Tip #5: Set up a permanent swap file
This is kind of a tech-geek option, so not everyone will want to try it. It's actually pretty easy, though, and can make a noticeable improvement on not only CFS3 but all of the games and applications you run. Basically, Windows uses space on your hard drive to create a file that simulates extra memory whenever applications need it. The default is for Windows to manage this file dynamically. Unfortunately, this uses some system resources, so it slows things down. Also, the changing size of this file can cause things that get written to the HD to be fragmented.
If you have more than one gigabyte of empty space on your hard drive, and you have recently defragmented that hard drive, setting up a swap file can make a big difference. If you are noticing that your hard drive light is on while you're playing the game, which shows that your system is reading and writing from the drive, this can help a lot! Here's what you do:
Windows XP:
1.      Click the Start button on your task bar, right-click My Computer, and select Properties from the menu. This will bring up the System Properties window.
2.      Select the Advanced tab and click the button to change the settings for Performance (the one that mentions virtual memory).
3.      Select the Advanced tab, then click the Change button for Virtual Memory. By default it will have the radio button "System Managed Size" selected.
4.      Select Custom Size, type "1024" into both the Initial Size and the Maximum Size boxes, then click OK on all of the dialog boxes until the System Properties window is closed.
NOTE:  If you have XP and the properties on your Start menu are set to Classic Start Menu, you should follow the Windows 98 steps below.
Windows 98/Me:
1.      Right-click the My Computer icon on your desktop and select Properties from the menu.
2.      Select the tab marked "Performance" and click the button marked Virtual Memory.
3.      Click the radio button that says "Let me specify my own virtual memory settings."
4.      Set the values in both the Minimum and Maximum fields to 1024, then click OK on all of the dialog boxes to apply the settings.
Tip #6: Turn down Clouds
Clouds in CFS3 are really gorgeous. Gorgeous enough, in fact, that even if you slide the Cloud Quality slider one or two notches to the left, they still look really good. If your frame rate is low overall, or if you notice significant slowdowns when there is bad weather present, try turning down Cloud Quality.
1.      Click the Options menu and select Display Options.
2.      Click the Image Quality tab and slide the Clouds Quality slider one or two notches to the left.
3.      After you've done this, test whether you like the changes by clicking Quick Combat and changing the weather to 7/8 Broken Clouds in the Location dialog box, then flying the mission. While the detail of clouds is lowered somewhat, and the clouds only draw at full detail near you, the change will have a modest effect on the look of the game, even though it significantly lowers the work your machine is doing.
Tip #7: Lower Terrain Detail and/or Scenery Detail but turn up Resolution.
In general, the amount of data that high settings on Terrain and Scenery Detail send to the video card is more of a problem than running at a higher screen resolution, so you may be able to dial down these settings but play at a higher resolution. This lowers the overall quality less than simply turning down the detail.
If you tend to have lower frame rates than you like or experience a great deal of stuttering, this may help you. For those of us who have good 3D cards that are not quite at the top of the chart anymore, this is particularly useful because it makes better use of the limited video RAM.
1.      Set Scenery Detail and/or Terrain Detail down one or two notches. (You can set Scenery Detail all the way to the right, but don't set Terrain Detail below 2 unless you have to, because the detail textures which begin at 2 make a noticeable improvement to the look of the game.)
2.      Make sure your resolution is set to at least 1024x768. If it's already set at that level, try bumping it to the next higher resolution your card supports. This should provide better performance.
Of course, it's a good idea to play around with the Image Quality sliders on your own as well. Tastes vary, and you may find that the balance between appearance and speed is a bit different from what others recommend, or that one type of detail is much more important to you than another. Experiment to find a compromise you like.
Tip #8: Turn off Scenery and Terrain Lighting
Scenery and terrain lighting is pretty subtle. It can make those screenshots, especially at dawn and dusk, look better, but you're not likely to notice it much in combat. Turning it off makes a modest frame rate improvement, but without any dramatic loss in appearance.
If you aren't happy with your frame rate give it a try. It's a very easy change to make; on most machines, the improvement in frame rate is small but noticeable. Just uncheck the Terrain and Scenery Lighting checkbox in the Image Quality dialog box. Note that it can take quite a while for the screen to update after you accept this change.
Tip #9: Turn off Shadows
Shadows are cool and they can be helpful for low-level flying. They also cost you several frames per second, so in your search for better performance, they're a clear target of opportunity. This is a sure-fire way to help out your frame rate, but only you can decide whether it is worth it or not. It's an easy change, so if you are in doubt, try it out.
Just uncheck the Shadows checkbox in the Image Quality dialog. Try the game out and see how badly you miss the shadows (if at all).
Tip #10: Turn off Dual Pass Rendering
This tip requires using the CFS3Config tool, and it's a bit more hardcore. It will improve your frame rate a bit, and it will make clouds look better to boot. This option may not work with all 3D cards, so you may have to back the change out if it causes problems.
If you have a fairly new 3D card, you ought to try this out. It's fairly easy to undo the change if it causes problems, and you'll see a noticeable improvement on cards that support it.
1.      Make sure CFS3 is not running.
2.      Click the Start button on your taskbar. From All Programs/Microsoft Games/Combat Flight Simulator 3, choose Run CFS3Config.
3.      Once the config utility opens, click the File menu and select Custom Settings. Click OK when the alert comes up to warn you that you can do bad things if you aren't careful. (We'll keep you safe!)
4.      Click the Window menu item and select Overrides. A little less than half way down the list, you will see Dual Pass Render, which is checked. Uncheck this box, then check the one for the choice directly below it, High Resolution Z-Buffer.
5.      Click OK and then use the File menu to quit CFS3Config.
If the game doesn't run, or the change causes erratic behavior, you can always restore the original settings by running CFS3Config again and selecting Default Settings from the file menu.
If you decide to upgrade…
You may decide that you really want to upgrade your system to improve your performance and you're wondering what you should get. Well, the two things that are most likely to improve your CFS3 experience are a good 3D card and more system RAM. Having a 3D card with a minimum of 64MB of video RAM will lower the amount of time spent moving textures to the card. Having more system RAM will mean that more data is in memory and doesn't have to be loaded from the hard drive. Of course, if data is being loaded from the hard drive, it helps if the hard drive is a nice, fast one. Therefore, you might want to consider upgrading your hard drive or just adding a second, faster hard drive to your system. If you do the latter, you'll want to move either CFS3 or your swap file to that drive; you'll get the biggest improvements if both are not on the same drive.
Until next time...
These aren't all of the things to try, but they will give you a good place to start. Watch CFSInsider for future articles and suggestions.

thanks Pete!
like I said In my first e-mai I only had the CFS3 for 1 day.
Unfortunatly I've reached the conlusion CFS 3 is much to heavy for my machine. I can get it runing on 30 fps but without nearly any grafic detal 

That's something we should blame Microsoft about because of their misleading info on the game cover, the one about the minimum systems requirements. IL - 2 is more honest. It had the same systems requirements but the ideal system also showed up on the cover... and it made me not buying the game since it was about 2x the system I had.

Still, I can play the game but with endless loading times, some ocasional freezing and a jerky Warp mode.

From my past experience I know when a game doesnt run well the first time... it's too heavy for your machine.