FSX FAQ (Part 1)

Q:  What the heck is the FSX FAQ?

A:  This will be a living document designed to answer frequently asked questions about Flight Simulator X.  I am not an expert in every field regarding Flight Simulator. I am merely the technical art lead for the studio.  So my main focus will be in answering art-related SDK type questions.  I will however try to cover some other areas as well.  Since this is a living document, it will grow and develop with the life of the product.  Likely it will get too big to navigate as one document (hence the "Part 1" above).  The first question after this one will be the most recent question I have answered, so if you recognize the question then you don't have to read any further.  Enjoy!

Q:  Where the heck did all the .cfg files go?

A:  For security reasons as well as organizational and multi-user scenarios, we moved all of the configs.  The FSX.cfg now lives here:  C:\Documents and Settings\[YourUserName]\Application Data\Microsoft\FSX.  The scenery.cfg now lives here:  C:\Documents and Settings\All Users\Application Data\Microsoft\FSX. 

Q:  How do I view the 2d panel in an aspect ratio besides 4:3 without it stretching and looking funny?

A:  For reasons why we didn't author multiple resolution 2d panels, see my related blog post. There are two ways of doing this:

1.  Put the game into "windowed" mode and rescale the window to 4:3 aspect ratio when flying with 2d Panels turned on.  Admittedly, this is annoying and a bit of a hack, but if you really don't like stretched panels and no blank space, it will do the trick.

2.  You can turn off panel stretching in FSX.CFG:



Q:  I keep reading about "the blurries" on the various Flightsim forums.  What are they and how do I get rid of them?

A:  Ah, the mythical (okay, not so mythical) "blurries".  What better way to start off then with this oft-complained about issue.  I will say that great steps have been taken during this product cycle to eliminate this problem.  However, there are still a few cases where the blurries appear.  Our excellent terrain developer Adam Szofran has put a post on Avsim that answers this question very clearly, and without further ado, here it is:

"During the development of Flight Simulator X (FSX), we observed the following conditions that could cause the blurries:

1. Inadequate CPU resources being allocated to the terrain texture loader, causing high-resolution textures to load very slowly, leaving low-resolution textures on the terrain.

2. Exhaustion of video memory, causing high-resolution mipmaps to be dropped in favor of lower-resolution mipmaps.

3. Poor bilinear, trilinear, or anisotropic filtering parameters, causing overaggressive mipping of textures viewed at oblique angles, such as distant terrain near the horizon.

Now I'd like to address each one of these problems in turn.

1. Inadequate CPU resources for the terrain texture loader.

The symptom of this problem is increasingly blurry terrain textures the further and faster you fly. When you slow down or stop, high-resolution textures eventually appear after some delay. This is probably the more traditional and most frequent cause of the blurries people have seen in Combat Flight Simulator 2 (CFS2), Flight Simulator 2002 (FS8), and Flight Simulator 2004 (FS9). This problem was caused by the scheduler for background tasks in the FS engine putting too much emphasis on maintaining high and even frame rates and not enough emphasis on preventing a backlog of background work, such as loading terrain textures.

To reduce this cause of the blurries, we reworked how Flight Simulator's scheduler prioritizes background tasks in FSX. Now much more CPU time is devoted to loading scenery data, including terrain textures, at the expense of somewhat lower frame rates. These changes occurred after the beta and demo builds went public, so you'll have to wait until the final version of FSX becomes available before seeing the improvement. In my opinion, this change has mostly solved this cause of the blurries, although the scenery loader can still get behind at extremely low frame rates (less than 10 fps) or at very large airspeeds (faster than 600 knots).

There are several ways to adjust how much CPU time FS devotes to loading scenery and textures. The easiest way is to set the target frame rate slider to a value that your machine can consistently achieve. The lower you set the slider, the more CPU time is diverted from rendering to loading data. Another thing you can do is to modify the following variable in FSX.CFG:


This variable determines the amount of CPU time given to loading scenery data as a fraction of the time spent rendering. For example, the default value of 0.33 means that for every 3 milliseconds spent rendering, FS will give 1 millisecond to the scenery loader. If necessary, you can use a larger value to devote more time to loading. Or, if you don't have a problem with the blurries and you want slightly higher frame rates, then you can use a smaller value. Again, this variable is only available in the final release version of FSX and is not available in the beta or demo.

2. Exhaustion of video memory.

I recently posted about this in another thread on AvSim entitled "Blurries still there :(". If a particular scene requires more video memory than your video card has available, the Flight Simulator graphics engine has no choice but to remove some of the highest resolution mipmaps from video memory to save space, leaving only lower-resolution mipmaps for rendering. This usually appears as a sudden change. One moment, all the textures in the scene are sharp and full-resolution and suddenly everything becomes more blurry. It can also get progressively worse over several frames as FS works to fit more textures into video memory.

There are several ways to combat this problem.

a) If you are running at a very high screen resolution, lower it slightly to free up additional video memory.

b) Some video cards use lots of video memory for anti-aliasing, so try turning it off.

c) Turn down the setting of the "Global Max Texture Size" slider.

d) Lower the setting of the AutoGen and scenery complexity sliders.

e) Reduce the setting of the terrain texture resolution slider.

f) Turn down the amount of AI traffic.

3. Poor filtering settings.

Unfortunately, not all video cards and drivers respond the same way when Flight Simulator interacts with Direct3D to set up bilinear, trilinear, or anisotropic filtering. This means that in spite of our best efforts, the texture filter on your video card may not be set up to perform optimally. This can result in textures looking excessively blurry when viewed at an oblique angle. To fix this, try each of the different filter modes (bilinear, trilinear, anisotropic) to see if any of them perform better. If not, then try overriding Flight Simulator's filter settings with the settings in your display driver. You can do this with ATI and NVIDIA drivers by clicking on the ATI or NVIDIA icon in the tray next to the clock on your desktop and making the appropriate selections."

Q:  Why does my totally amazing dual core Ahtlon machine show up with all of the settings set to the lowest possible setting?

A:  When we sniff our user's machine to determine performance buckets, we look at a few different things.  As the most important part of the equation we look at video memory, system memory and CPU.  For some reason, (I don't know all the technical issues behind this, so I won't even venture a guess) this information is not available for AMD chipsets, which puts a big fat zero in part of the equation.  So even if you have the most smoking graphics card ever and a terrabyte of system memory, the CPU still shows up as nothing, which means that there's nothing to process all this information, which means your default settings go all the way to zero.  This is an annoying problem (especially since both of my machines are Athlons) but the alternative is to make some arbitrary assumption that may end up giving the end user a very poor experience right out of the box.  Granted, really low resolution on everything is not the best experience, but it is better than a really pretty slide show.  Which brings me to:

Q:  I've got a brand new machine with the best hardware available.  Why can't I put all of my sliders to the max and get 60 frames per second?

A:  Flight Simulator is a very different product than most games.  The shelf life of most games is about 6 months at the most.  Occasionally you'll get some mod communities (Half-Life and Counterstrike come to mind) that will extend the shelf life of a game to a couple of years.  However, take a quick jaunt over to some of the forums (Avsim, Flightsim.com, etc.) and you'll find people who are still flying FS2000 six years later because they have $2500 invested in add-ons.  Because our shelf life is so long, we tend to push the boundaries of what you can do with the performance of new machines.  As with every release of Flightsim we've ever done, it will be about 2 years or so before hardware catches up.  We do this very deliberately because as people upgrade their machines down the road (and are still playing Flightsim), we want their experience to develop and grow.

Q:  Yeah, but if you are aiming for hardware 2 years from now, doesn't mean that my current experience will be sucky?

A:  In short, no.  In long, we make a very special effort to make sure the default experience on your machine for Flight Simulator X right out of the box is equivalent to FS2004, with a lot more going on.  As an example, on my machine in FS2004, I can slide the autogen slider all the way to the right and get great performance.  In FSX, I can slide it somewhere in the middle and get great performance.  This would at first blush seem like FSX is performing worse than FS2004.  The reality is that the highest setting of Autogen in FS2004 meant that 600 objects per kilometer are being rendered.  In FSX, the highest setting means that 6000 objects are being rendered.  So even at the mid point in FSX, you're likely getting twice the autogen density as you were in FS2004.  Additionally, you may be rendering living world traffic in the form of boats, cars on roads and vehicles at airports which didn't even exist in FS2004.  Also, if you're running a 2.0 shader card or better, you're also rendering full per-pixel shaders with normal maps, specular and reflection that you weren't rendering in FS2004.  Plus, you're not getting "the blurries" like you were in FS2004 and you're rendering full 1 meter per-pixel resolution terrain textures which were at 5 meters per-pixel in FS2004 (and were still not loading in fast enough). 

So no, you can't crank all the sliders up to the max and expect performance to be great.  However if you play with the sliders a little bit, you will definitely get a better experience than you did in FS2004, with a richer, more realistic world that still performs great.  One of the sliders I recommend you play with is the target framerate slider.  I keep this at 20, get great performance, can crank the sliders up reasonably high, and really don't notice any kind of slow framerate at all.


Comments (46)

  1. Anonymous says:

    Well, since we’re just a week away from the official release of Flightsim in most of the world (sorry

  2. Anonymous says:

    I would be willing to bet it has to do with your graphics card drivers.  That’s often the cause of that kind of thing.  Do you have the latest drivers for your card?

  3. Anonymous says:

    It depends a lot on your settings.  You can’t crank everything up and autogen is a real killer at high levels.  Also, bloom can be a perf hog as can anything that requires a full screen second rendering pass.  Try adjusting.  I have basically the same setup as you and I run with autogen at a low-mid setting (which is still more dense than FS2004) and everything else cranked up pretty high and I get 20 fps pretty regularly.  What’s your graphics card?  I currently have a GeForce 6800 with only 256 Mb of memory and that seems to do the trick okay.

  4. Anonymous says:

    Hello Klaus,

    The system you are planning sounds great!  It is better than both my home and work machines, so it should do the trick.  As for the Vista / XP debate, Vista will be the only operating system with DX10, which we are currently optimizing for.  However, FSX wasn’t really a DX10 product (although SP2 does have some DX10-only features), so in that case either would work fine.  However, if you want to move forward with the times and with DX10, then Vista would have to be it.

    By the way, you’re english is fine.  Probably better than most of us here in the States.  ; )


  5. Anonymous says:

    We can’t record an infinite number of data points during flight, so you may be seeing artifacting due to compression.  If it is very severe, then it may be another bug.  I’ll try to look into it.

  6. Anonymous says:

    What kind of video card are you running?  What drivers?  I suspect that the problem lies somewhere in that combination of hardware / software.  We’ve found a few instances where different video card manufacturers approach different effects in different ways.  We tried to solve for the most cards with the most recent drivers, so updating might help out a bit.

  7. Anonymous says:

    I’ll look into this.  Thanks for the post.

  8. Anonymous says:

    It really bothers me to see MS design a game for hardware two years out. I want to play the game today (when I bought and PAID for it), not two years from now.

    Do users complain that with their latest hardware that FS2004 runs too smoothly, frame rates are too fast and and it just looks too good?

    You don’t see console game designers selling games for the next generation of consoles and when the performance stinks telling the users "Just wait for the next console and it will look great".

    David E.

  9. Ken Stallings says:

    That’s one of the finest descriptions of the macro issues in the Flight Simulator series as I have read.  And based on the experience with the Demo’s, I’d say it’s right on target also.

  10. EDDIE says:

    Thank you for writing this up – it’s great insight to read such details.

    I am sad to hear about the AMD cpus, but oh well. What I am actually more worried about, frankly, is the apparent lack of multi-threading during gameplay – my G15 lcd monitor in the game shows my AMD 3200+ dual core pegged on one cpu and the other virtually idle 🙁

    I definitely know that making things multi-threaded is no easy task, but I hope the devs have been thinking about this and can get us something!

  11. deltanovember says:

    Thanks for starting this Adrian it will help

    a great deal.

     Good to see you back posting again.



  12. William Jibby says:

    Very good explanation.  This is needed to understand FSX.


    William Jibby Jib01/02

  13. Thad says:

    Thanks for the detailed info on FSX. This should be required reading on all the flight sim sites. I’ve got FSX’s sliders set to medium/medium-high and it certainly looks better than FS9 maxed IMO with good FPS(~20).

  14. Barry Geller says:

    Please add me to your list.



  15. Scott says:

    Thanks for a common sense explanation. I’m looking forward to my copy of FSX and will no doubt enjoy it more armed with your information

  16. Mikeee says:

    yeah thanx for the indepth explanation about frame rate hits and display tweaking etc. i am happy with fsx but i do get some weired graphical glitches like at night as i am flying towards or reletive to the airport my whole screen gets washed out with white until i point the nose of the aircraft away and then everything goes back to normal. i was wondering if this had anything to do with the light bloom effect. ?

  17. Christopher N. Dittmar says:

    For the 70 USD FSX Deluxe cost me I still think it has a lot of potential.  The only issue I have with it is the type of placement on the textures and their sizes.  Fortunately i saved some performance by downloading some reduced size autogen and cloud textures, but does Colorado have to look like the Sahara desert?  I mean – wow – it can’t be an "FS" or landclass limitation because it looked bloody awesome in FS 2004.

    Just out of curiosity, though, you say that the line FIBER_FRAME_TIME_FRACTION=0.33 exists in the final release version of the product — in the FSX.cfg file?  I have this file curently open and doing a search for even the word "FIBER" brings nothing up.  I searched the entire string and all of the words individually and this entry is not in the config.  Bear in mind, yes, I have the final release DVD in the deluxe package (shouldn’t make a difference what package I have though — the only difference between standard and deluxe is a few aircraft).  This looks like a good tweak, but I do not want to add something into the file that is not supposed to be there.  Did MS take it out of this version?

    Oh — BTW — I am using the US version if that matters.

  18. Sven Ohrberg says:

    Thanks for the info, but what about multi-core CPUs? I have an AMD 4800+ but FSX only make use of one core, with the other core just idle. Can this be fixed in a future patch, or are we not going to use our multi-core CPUs before Flight Simulator 11?


    <As with every release of Flightsim we’ve ever done, it will be about 2 years or so before hardware catches up. >

    If so, when will dual core programming "catch up" to our hardware?

  19. Glenn Larsson says:

    I for one is very happy to see that some work have been spent on making it take advantage of future hardware.

    However, that is not why i posted. Could you add something about product activation?

    According to this:


    As i read it, we will only be able to migrate to ONE new hardware configuration – or – do ONE hardware upgrade, then our 2 activations are – *poff* – gone.

    Why didnt you just bind the activation key to one specific Windows licensenumber instead of mixing it into something that changes at times like the hardware configuration of a computer?

    I mean, i dont even dare to install my new Logitech mouse drivers for fearing that FSX will notice a change in the DX config and say "Hold it mate, i smell a change!"

    I am very eager to hear about what the effects are since i am going to reinstall my gaming PC in the near future and add additional hardware like a joystick or a new gfx card, and one activation is already gone…

    Btw, the game (Deluxe, European) runs somewhat smoothly on a Athlon 3200, 1 gig memory, 6600GT/256, DX9, but at times it runs very slowly, mainly when entering larger cities like London and Paris.

    Oh, and maby a note on where we can report bugs would be nice.

  20. FSX_Knocker says:

    Dear  Christopher N. Dittmar ,

    I believe you have to add that line manully ..

    I have read it somewhere in the net…

  21. Peter Tikoian says:

    I have tried many many combinations to get my frame rate and performance the same as fs9 and I did not succeed. I have a Dell Dimension 8300 with a 3.4ghz processer,2000 memory and a 256 mb ATI video card. All my sliders were maxed out and I enjoyed fs6 to the max.  Now with FSX my fram rate is between 8.0 and 12.0 with the maximun slider on "Medium Low". I am 86 years old and I guess I will never get to enjoy FSX. You developers were looking far into in the future and feft us old gotes out to pasture. I still have FS 1.0.

    Pete- not a happy camper

  22. mo says:

    For Pete

    has some updates, info on improving framerate etc

    Also defintely good tweak ideas for fsx


  23. Dave says:

    I’m having a lot of trouble reinstalling FSX. I wasn’t aware of the consequences when I removed FSX from Add/Remove Programs and the uninstall did not finish, leaving me with a partially installed FSX. Now, when I try to reinstall, it loads for about 60 seconds and then gives me an Error 1722 message.

    Microsoft has a solution to the Error 1722 message, but it’s too complicated for me to follow. One of the stumbling blocks is the last instruction in which one must open the Command Prompt and type in some MS directions which are always rejected as being incorrect. Can anyone help me solve my reinstallation problem or am I stuck with this $70 useless beast?

  24. Dan_IT says:

    I can not find the fsx.cfg file any where on my computer.  I just put together a fairly good computer, but with AMD.  I have 512 mg on the video card, 2 mg of Ram and a 4200 amd processor and still can not get close to 20 fps.  Anybody have any ideas.  I also have a SATA drive.

  25. Pat Davies says:

    Why does my screen keep freezing when flying any ideas

  26. ...1 says:

    Very nice site! Good work.

  27. Scott says:

    FSX and Vista

    What is going on? Every time I start FSX under Vista I get a message that the display is going out of Aero mode due to an incompatibility problem, performance is also less than stellar. My FSX box has Vista listed under the supported systems.

  28. ...1 says:

    Du musst ein Fachmann sein – wirklich guter Aufstellungsort, den du hast!

  29. ...1 says:

    pagine piuttosto informative, piacevoli =)

  30. ...1 says:

    Great site! Good luck to it’s owner!

  31. wilderbeast says:

    After flying fsx for over sixty hours the log book has stopped adding any new entries. When flying missions it still adds trophies, have any fellow pilots had the same problem

  32. ...1 says:

    Mine has just stopped on 45 hours….HEEELLLPPPP Only thing I’ve done to FSX lately is install SP1……..

  33. Midhir says:

    I have had this exact problem.  The posted solution I’ve seen is to rename or remove your My DocumentsFlight Simulator X FilesLogbook.bin

    As to the missing fsx.cfg file, I don’t think it’s accessible outside of the resource file it is contained in, but you can create your own fsx.cfg with just the entries you need and drop it right into your main fsx folder.

  34. Jim Sims says:

    I am retired (77) and have been enjoying FSX.   I am new at this and have down loaded several airliner.  I braved downloading the XB-70.  It is a beautiful plane but unlike others, the autopilot has a terrible time with proposing up and down not finding or stopping at the assigned altitude.  It is most annoying and must be a glitch in the programming.  Other friends who have the plane find the same problem. I hate to be long winded but I cant fine a solution anywhere.  IS THERE ONE? AND CAN YOU HELP IN ANYWAY?  Thank you for any comment you may have.


  35. skinnypete says:

    how do you open engine panels/covers?

  36. skinnypete says:

    sry jim i dont have that plane.

    by the way does anyone know how to open the engine covers/panels in fsx?

  37. Robert Adams says:

    Been reading all the forums regarding Video problems with FSX…

    Computer Aspire L5100 Bios Phoenix Award Bios v6.00pg

    Processor AMD 64×2 Dual Core 4200+ 2cup’s at 2.2gh Memory 2814mb ram page file 1101 mb’s 4720 mb available…Direct X version Direct X10..690 chipset with ATI Radeon X1250 video 1407mb running screen at 1680×1050 direct drawn acceleration on…Direct 3D acceleration on…AGP Texture acceleration ON…

    Same problem as others…Accessing FSX the AERO video is switch to ACER visual basic…

    I have attempted various settings to solve this particular problem…I haven’t seen a solution as of this writing…While flying the aircraft, If I move the mouse around on the various knobs and switches to make changes in the aircraft settings, then the screen will change to all white, black back to white and after about 2 or 3 seconds will reset back to normal…

  38. elstavd says:

    Hi, if i record a clip during a free flight, and review it afterwards, the movements of the aircrafts are not the same as the actual movements I made with the aircrafts. How do i fix this problem?  It seems as if the pc filters out the movements i make

  39. Klaus Dahlem says:

    Hi, I want to build a specified FSX-PC to use it on my own. Perhaps I even want to distribute it later if it works contentedly. But in matter of fact I asked 10 people about and got 10 different answers. So I want to show you what I have choosen and ask you if you could give me an advice to improve my selection.

    Mainboard: Gigabite X38-DQ6, CPU: Intel Core2 Quad

    Q 9450, RAM DDR2, 4GB, Grafic: Gainward 8800GT, 1024 MB, Bliss Golden Selection, Chip G92. FSX with SP1 and Accel.Kit. The result should be at least 30 fps with all contoller on Ultra, and with some Add-Ons over a capitel. Short said, a PC as strong as it is needed. And what is the best operation system for FSX. Windows XP, Vista 32, or Vista 64?

    Can you help me with your advise? I am coming from germany and my english ist not so good anymore. So if you find some mistakes, you can keep them ;-). Best regards Klaus Dahlem

  40. angelos says:

    how can i make a fs2004 file play on fsx?

  41. algeggi says:


    I have a new Pc with Vista and FSX installed. I would like to know if I need to install SP1 and SP2.

    Thanks Algeggi

  42. gmes300 says:


  43. mustafa sazak says:

    whatever you recommend, it doesnt work. Because my graphic card is onboard :D:D:D:D

    yay yay yay yuppy

  44. CAN says:

    Hello everyone!

    I ve built a machine for FSX, trusting the graphic card Zotac GeForce 9800GTX + AMP!

    Gigabyte P45 Motherboard

    Intel Q9400 QuadCore

    4 GB RAM

    Windows XP Home

    FSX Service Pack 2

    But the result is not satisfying.

    In ultra high setting (light bloom off and some of the texture specifications are not on full), while the stormy weather selected the frame rate dumps to 8, even 6.

    I’m getting mad of this, what can I do to improve the performance?

  45. saveloy says:

    Hello there,

    recently i purchased a quad core with Vista purely to run fsx better! I have fsx installed on a slave drive with XP (from my old pc). My question is how do i get my vista to accept accessing the XP hard drive without an error mentioning activation!!

  46. Umper says:

    "Plus, you’re not getting "the blurries" like you were in FS2004"

    Lol, I didn’t get blurries in 2004, but I sure do now, and that’s with a AMD quad core, 7 gigs of ram, and a radeon 4870 with another gig.  Face it, blurries galore forever….rofl

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