OpusFSI Flight Simulator Interface for and

OpusFSI_Overview  OpusFSI_User_Guide  OpusFSI_Getting_Started_Single_PC  OpusFSI_Getting_Started_Networked_PCs  OpusFSI_Live_Weather  OpusFSI_Live_Camera  OpusFSI_ButtKicker

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Getting Started - Networked PCs (continued)


FSX Computer System Settings

Recommended Settings for FSISERVER and FSICLIENT Systems

 fsx.cfg File Settings

You must edit your fsx.cfg file, this file can be found in,

 c:\Users\<your account name>\AppData\Roaming\Microsoft\FSX

If you can't see the AppData folder within Windows Explorer then you will need to change the View settings as follows,

 Organize - Folder and Search Options - View - Enable the 'Show hidden files, folders, and drives' option.

On all FSX systems we recommend you specify the following fields within in the fsx.cfg file,





These setting will allow FSX to make better use of the 64-bit memory environment with >2GB memory, also supports modern day wide aspect screens for addons such as PMDG 737NGX. 

We also recommend you optimize all of your fsx.cfg files using,



Recommended Settings for FSICLIENT Systems using Live View

The Flight Simulator program on all client 'Live View' PCs is going to be used to provide nothing more than a scenic display. It is therefore highly recommended that you to turn off all FSX settings that are likely to have an adverse effect on the client system's display performance.

In order to see the full synchronized effects of Live View users may need to save a default flight with all engines running on each client system to ensure the aircraft is powered up correctly and ready to fly.

To provide the smoothest possible 'Live View' experience on each of the FSICLIENT machines, the Flight Simulator should be configured with the following recommended settings.

Aircraft, Select  Aircraft ...

Select a simple stock or dummy simulator aircraft (e.g. the stock C172 or B737).

Aircraft, Realism Settings ...

Turn all 'Flight model' settings to their easiest settings. Enable the 'Ignore crashes and damage' option. Enable 'Unlimited fuel'. Turn off all 'Special Effects' and 'Flight Controls' settings.

Options, Settings, Display, Graphics ...

To see wing flex you must select advanced animations.

Set the 'Target frame rate' on the server and all client PCs to UNLIMITED.

A word of caution, if you set your target frame rate too high on either the FSISERVER or FSICLIENT systems then you may experience problems with the snow and rain effects. That is, you may see some snow and rain falling vertically whilst moving. This is an FSX problem and the only solution we've found so far is to restrict the machine's frame rate. If this is a problem then a setting of 20fps to 60fps should result in a smooth operation. On slower systems, or systems with slow hard disk drives, you may also notice the occasional screen flicker. Once again lowering the target frame rate should help.

If you experience lag on your client systems you may have to lower the frame rate on your server.

Options, Settings, Display, Aircraft ...

Unless you have a specific reason for wanting to see the cockpit view; select the 2-D instrument panel as the default cockpit view and set the 2-D panel transparency to 100%.

If you only want scenic views and not cockpit or external aircraft views on your client systems then you can optimize the performance even further by selecting a simple aircraft type (e.g. the standard Cessna 172 or Boeing 737).

To speed up the loading of FSX you can remove all unused aircraft from the standard  'Microsoft Flight Simulator X\SimObjects\Airplanes\' folder.

My advice would be to create a new 'Microsoft Flight Simulator X\SimObjects\Airplanes_Removed\' folder and move all the unused airplane sub-folders into there.

Options, Settings, Display, Weather ...

The weather options must be identical to the server, i.e. matching cloud draw distance, cloud detail etc. Turn off the 'Thermal visualization' option. Turn off the  'Download winds aloft with real-world weather' option. Enable turbulence and thermal effects on the aircraft. Set the 'Rate at which weather changes over time' to zero (No Change). We recommend you set the 'Cloud draw distance' to between 80mi/128km and 100mi/160km. If you generally fly at a higher altitudes then the higher setting is preferable but if you fly at lower altitudes then the lower setting is preferable.

Options, Settings, Display, Traffic ...

Disable all AI traffic.


Options, Settings, General ...

Turn off the 'Pause on task switch' option. You do not need to pause or set FSX into slew mode, these modes have no effect on the system's performance.

Options, Settings, Sound ...

Turn off all sound by deselecting all sound options (e.g. Engines, Cockpit, Environment and Voice) and turn off both the 'Play user interface sounds' and 'Play user interface music' options.

World, Weather...

Select Weather Themes and set to Clear Skies.


Virus Checkers

We recommend turning off all virus checkers whilst running FSX since they can have a serious effect on performance.


Performance using Live View

Please remember you cannot just rely on the frame rate measurements because FSX/P3D will always give a fairly high priority to updating the screen. On networked systems you must always give your server's FSX/P3D adequate CPU capacity to perform other essential tasks, such as issuing the very important postion updates. If your system has the stutters, then it is these infrequent position updates from the server's FSX/P3D that is producing them!

If you are using P3D then you must enable the PDK Interface to provide a more efficient Live View interface. Refer to the OPUSPDK_SETUP text file to set up the Prepar3D OpusPDK interface.

OpusFSI has very little impact on the FSX performance and can generally communicate the position updates as fast as FSX/P3D can issue them. So if you are having stutter problems then you should investigate other possible causes. For instance, make sure you are not running any software (AV or Firewall) that could be interfering with the FSISERVER program's piped IPC link communications. Are you draining the FSX performance by displaying too many views on the server, in-house we never drive more than the single view on the server. Remember if you must have a wide panoramic view then you can always install a wide view screen or use three identical display screens with a TrippleHead2Go type product, in which case, as far as the sim is concerned, you are still driving a single main view, just one with a large pixel width. Other possible causes could be your server's PC spec (is it up to the job), insufficient memory (Windows 7 64-bit + loads of memory is highly recommended), do you have a poor or slow network connection (this is the age of Gigabit LANs - there's no excuse), is your actual aircraft sim well behaved (or does it hog the processor?), is your scenery too complex for your system, or have you been over enthusiastic with the FSX/P3D settings.  

Try turning OFF Live Traffic and restarting the FSISERVER.

To give you some idea as to what performance figures you should be aiming to achieve, here are my details recorded using a high-spec server PC with a single ASUS gaming laptop client (I have included the actual server computer and client laptop specs below).

First note, the client position update rates (most important) are displayed in the client's Spy window for the 'Networked Live View - Position and Attitude' application link when the aircraft is in motion. Remember OpusFSI generally updates the client systems as fast as the server FSX/P3D program can issue position updates.

On the ground

Sitting on the runway in the Real Air SF260 at UK2000 East Midlands Extreme airport,
Server Frame Rates: 50+ fps (67% full screen view), or 46 fps (2560 x 1600 full screen view)
Client Frame Rates: 40 to 50 fps (approx 1024 x 1040 view), or 28 fps (1920 x 1080 full screen view)
Client Position Updates: For FSX smooth at 50 to 60 updates per second. For P3D 8-20 updates per second with the server Live View Scan Rate (server Config dialog) set to zero.

In the Air

Cruising at 4000ft in the Real Air SF260 (on a very cloudy day),
Server Frame Rates: 60 to 100 fps (67% full screen view), or 65 fps (2560 x 1600 full screen view)
Client Frame Rates: 60 to 120 fps (approx 1024 x 1040 view), or 45 fps (1920 x 1080 full screen view)
Client Position Updates: Smooth at 80 to 120 updates per second, or 70 to 80 updates per second (full screen view)

In both cases I have my target frames rates set to Unlimited. On my server I am driving into a single 2560 x 1600, 32-bit Virtual Cockpit view, and my client laptop is driving a single 1920 x 1080, 32-bit 2D cockpit 'scenic' view.

Server PC:

Windows 7 64-bit
Intel Six Core, i7 X990 CPU @ 3.47GHz
24GB memory
2 x 224GB Kingston SSD (FSX on one, P3D on the other, every thing else on drive C)
2 x NVidia GeForce GTX580s

ASUS Client Gaming Laptop:

Windows 7 64-bit
Intel Quad Core, i7 2630QM CPU @ 2GHz
12GB memory
2 x 700GB HDD
NVidia GeForce GTX560M

Client Lenovo Gaming Laptop:
Windows 10 64-bit
Intel Xeon, E3-1505M CPU @ 2.8GHz
16GB memory
2 x 500GB SSD
NVidia Quadro M4000M

My Server's FSX Settings:

Target Frame Rates: Unlimited
Filtering: Anisotropic
Anti-aliasing: ON
Global Texture: V.High
Advanced Animations: ON

Level of Detail: Medium
Mesh Complexity: 100
Mesh Resolution: 2m
Texture: 7cm
Water Effects: High 1.x
Scenery: Very Dense
Autogen: Sparse
Ground Shadows: OFF
Special Effects: High

Cloud Drawing: 110mi/176km
Thermal Vis: NONE
Disable Turb: YES
Detailed Clouds: YES
Cloud Cover: MAX

Airline: 32%
GA: 16%
Airport: Minimum
Road: 4%
Ships: 4%
Boats: 3%

My client systems are set up in accordance with our Getting Started guide. Note also, I use Kingston Solid State Drives (SSDs) to give the fastest possible read performance for FSX and P3D. Do not load the operating system on these drives though since the write performance is quite poor.

My client system's view does not stutter with this setup and does not change if I add a second client system. On some systems we have set the target frame rates to 60 or Unlimited on the server and 24 on the client systems. You may have to play with yours. One hint - if you're flying along and the rain or snow is still falling vertically then FSX/P3D cannot cope so try lowering your target frame rate to 30 or less.  


Live View Test

These tests are designed to help you set up your Live View system and isolate problems within your server, network, or client systems. Make sure you have set up all systems in accordance with the Getting Started Guide for Networked Systems.

Pay careful attention to all the recommended sharing, permissions and security settings, remembering the share both the install drive and folders of OpusFSI and your simulator. Also pay attention to the recommended settings and optimisation of your client systems.

Starting Up

Run the simulator and load the flights on the server and all client systems. Your aircraft can be sat at an airport before starting the test, alternatively you may conduct the test with the aircraft positioned anywhere you want.

Your simulator should be run in Windowed Mode on all systems.

Run the FSISERVER program on your server and let it initialise, then run the FSICLIENT program on each client system you are going to test.

Allow all the systems to settle down with all client system simulator's fully initialised and positioned. You are now ready to conduct the Live View link tests.

To start the test, open the Configure dialog and click on the Live View Test button. The Live View Test dialog will be displayed and your simulator will be un-paused.

On the server you will not be needing your simulator display so just minimise it to the taskbar.

Testing The Link

Determine Your Optimum Update Rate ...

Close any Spy windows you have opened and ensure you have minimised your server's simulator to the taskbar.

Start off with the Update Rate slider in the centre position and tick each of the Pitch, Bank, and Yaw test options, then click the Start button. You should now see your client display jump to 500 feet above the surface and start moving in all three attitude axis. Let it run for a few seconds then click the Stop button. The client display should stop and reset straight and level without any significant delay. Adjust the Update Rate until you can run this test and Stop without any appreciable lag in the client response.

Once you have determined your optimum Update Rate open the Position & Attitude Spy window on your client system, start the test and make a note of the rough average number of Position Updates per second. Divide 1000 by this figure and set the ms rate in the Live View Scan Rate box provided in the Configure dialog e.g. 100 updates per second is 10 ms. For P3D you may need to set the Live View Scan Rate to zero.

Stuttering Client Display

Your client display should move fairly smoothly with no major stutters or abrupt changes in attitude.

If your client display stutters badly running the Live View Test on your Server then you most likely have a problem with either your network connection or your actual client simulator system, try conducting the Live View Test on your client system.

If your client display stutters badly whilst running the Live View Test on your Client then this will indicate your client simulator system cannot cope with the position and attitude updates. Please make sure you have optimised your client simulator system, stopped all unnecessary software including any virus scanners, selected a stock or dummy simulator aircraft (e.g. the stock C172 or B737). You could also try adjusting the simulator settings, changing the simulator's target frame rate etc. For P3D you may need to set the server  Live View Scan Rate to zero.


Update Rate

This slider will typically alter the update rate from between 50 updates per second (Slow) up to about 120+ updates per second. This slider should be adjusted so that there is no appreciable lag when Stopping the test.

If there is a lag then reduce the rate of updates sent from the server by adjusting the configurable scan rate (i.e. increase the value) in the server Configure dialog's Live View Scan Rate (ms).

Test Tick Boxes

The Test Pitch, Bank and Yaw tick boxes allow you to select each of the attitude modes individually.

Start Button

Click the Start button to start the test and vary the selected pitch, bank and yaw attitudes for the aircraft. At the start of a test the aircraft is automatically positioned 500 feet AGL.

Stop Button

Click the Stop button to terminate the test and recentre the aircraft.


Either click on the Quit button or the dialog's X to abort the test and close the Live View Test dialog.


FAQ and Troubleshooting

TypeInitialisation errors when running the FSICLIENT program

Navigate to the OpusFSI installation folder on your client and install the SimConnect libraries using the supplied SimConnect.msi file.

Can I use a Wi-Fi network ?

Yes you can, however you should note that a direct Wi-Fi link is only going to give you 54Mbps and a redirected link will operate at about 16 to 24Mbps. This may be faster than an ancient 1990s 10base-T network running at 10Mbps but nowadays everyone uses either 100Base-TX (100 Mbps) or a 1000Base-T gigabit LAN running at 1000Mbps (1Gbps). The modern cabled LANs are going to operate up to 64 times faster than the Wi-Fi link!

However, if you must use a Wi-Fi link (no LAN ports or Cat5 cable) then just make sure all the computer systems have the same workgroup set (Control Panel - System and Security - System - Change Settings - Change...) and configure the main server's computer name into the FSICLIENT programs. You will find the link works perfectly well with perhaps a few tiny jitters when taking off of flying fast and low (depends how good or busy your Wi-Fi link is).

My client system lags behind the server

The lag indicates the clients cannot keep up with the updates. The programs have 32K buffers for both receive and transmit over each IPC link, hence the possible back log. 

There are two solutions. The best is to reduce the rate of updates sent from the server by adjusting the configurable scan rate (i.e. increase the value) in the server Configure dialog's Live View Scan Rate (ms). The second solution is to occasionally pause using the 'P' key on the server, let everything catch up and then unpause, let things settle and the lag will then be gone. You can also use the pause key to measure the lag or amount of buffering at the client end. If the system is configured and tuned correctly there should never be any lag and both server and client should pause together almost instantly. If your system is set up correctly it should be able to cope with the throughput.  

We have a Live View test facility to help you tune your system.

Start up all the client FSX systems and the server FSX so that they are all up and running. Then start the FSISERVER program, let it settle, then each of the FSICLIENT programs. Once they connect their FSXs will normally reload to the new location, they will also resync after receiving their first weather update (necessary to ensure correct cloud sync). Once all the client systems are settled then you can force another weather update just before takeoff to make sure all is well and then you are ready to go.

It is very important to set up your client systems as per the Getting Started guides to optimise your client systems, this can have a dramatic impact on the performance. It also helps if you are displaying scenic views to select one of the simple FSX stock aircraft ( e.g. the C172 or B737), some people even use a dummy aircraft that has zero overheads. You may also try adjusting the target frames rates, either Unlimited or on slower systems you could even set 20 to 30. It's all about giving FSX more time to process the stream of position updates.

Also, if you are using Static Weather Themes and have paused the system for any length of time (>1min), then it would be best to select Weather on the FSISERVER and click Update Weather, this re-synchs everything including the cloud formations. The tell tale sign that one system has been paused too long is that you will get different cloud formations on the server and client system. Anytime this happens just re-sync via the Weather option in the FSISERVER program. If you don't pause this should never happen.

We also recommend not running anti-virus software since this can have a serious performance effect on the clients.

Can't get cameras or weather on the clients

You haven't set up your sharing and security permissions for Everyone on your server and client systems. Both the drive and the FSX/P3D install folder must be shared and accessible to the OpusFSI program. Hence you have no client weather (the client cannot copy the weather file), and you have no external aircraft view (the client cannot prepare your aircraft.cfg files).

You should also have the all the standard views available, so with a cockpit view on display on the client, hitting the S key four times should cycle to the custom external aircraft view. But this will only happen when the CameraDefinition has been appended to the aircraft.cfg files.

Both systems must be shared with all security permissions set as per this guide.

Win7 and XP networked systems

You may (or may not) experience problems if you have both Win7 and XP systems on your network. Removing the homegroup and reverting to standard networking may help.


and http://www.youtube.com/watch?v=VRY4_POp9zA


Please also refer to the FAQ in the OpusFSI_Getting_Started_Single_PC guide which can be found in the OpusFSI installation folder.


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