This is weird - I posted this same question yesterday but it seems to have completely disappeared. Anyway:

 

I have four networked OpusFSX clients with LiveView enabled. The displayed view on all of them, to some degree, lag behind the server. The lag may be nearly negligible, or may be as long as 3-4 seconds. Once a client starts to lag, it consistently stays lagged (i.e. a quarter-second lag stays that long; a 2 second lag stays that long) as long as I run the simulation session. The lag is present from startup forward. Each time I start FSX on the clients and then the FSXCLIENT.EXE app, the amount of lag I get on each client is not consistent from one sim session to another. During session 1 it may be that 'flightsim2' (one of the clients) has a 1/2 second lag and 'flightsim5' has a 1 second lag. After shutting down and restarting everything, during session 2 'flighsim2' might have 2 second lag and 'flightsim5' might have negligible lag. I've seen a couple of sessions where all of the clients were behaving with virtually zero lag, but most of my sim sessions have a least one client with severe (1-3 second) lag.

 

The server and all of the clients are on Intel i7 quad core CPUs at 3.4GHz with 8GB of RAM. No firewalls are running, no anti-virus is running, no other apps besides FSX and the OpusFSX server/clients are running. The systems are all sitting on a private 1GbE network. File sharing is correctly configured (in the sense that cameras and weather are being correctly controlled by the OpusFSX server process on all clients).

 

I don't know what steps to take to help me isolate what might be going on. Does anybody have any suggestions?

 

-M.

Extract from our FAQ ...

 

The client should never lag behind the server. You most probably forgot to start FSX on the client before the FSXCLIENT program started receiving updates from the FSXSERVER program on the main 'flying' PC. The updates will start a plenty as soon as the main system is up and running - if a client is connected it receives the updates irrespective of the state of its own local FSX.

 

The programs have 32K buffers for both receive and transmit over each IPC link, hence the possible back log. If this does happen, simply pause the main system using the 'P' key, then close and restart the FSXCLIENT program, the links should be re-established and the client system synchronized (please refer to the recommended start up procedures in the Getting Started guide).

 

Also, if you have paused the system for any length of time (>1min) and you are using Weather Themes, then it would be best to select Weather on the FSXSERVER and click OK, this re-synchs everything including the cloud formations. The tell tale sign that one system 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 FSXSERVER program. If you don't pause this should never happen.

 

Also please refer to the getting started guide, it is very important to set up your client systems as per the guide 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).

 

Regards

Cheryl

 

I normally start up all my client FSX systems and the server FSX so that they are all up and running. Then start the FSXSERVER program, let it settle, then each of the FSXCLIENT 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 I then force another weather update just before takeoff to make sure all is well and I'm then ready to go.

 

The lag indicates the clients cannot keep up with the updates. The Getting Started guide will help with this. Also choosing a simple FSX stock aircraft, some people 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.

 

If you suspect lag, then pause the server, let everything catch up and then unpause. But if your system is set up correctly it should be able to cope with the throughput.

 

Regards

Stephen

The answer for me was to reduce the frame rate on my server. I left all of the clients set at 'unlimited' and reduced the frame rate on the server to 40 fps. This seems to have completely solved the lag issue. I still get the occasional stutter from the clients, but I can live with that.

Hi Mark

 

Well done, we will make a note of that and include it in the guide. The remaining occasional stutter is actually coming from within your server's FSX. There is nothing you can do to elliminate it completely, just minimise it's occurrence, which seems exactly what you have done. Every now and then server FSX just stutters whilst issuing its position updates, it might be accessing scenery files or something, I don't know for sure but it happens on all systems.

 

You will have to send me an image (photo) of your system once you've got it all up and running fully. Just out of my personal interest, your system looks very interesting.

 

Regards

Stephen