Unstable Position Update Rates

[hrichbourg 0]

My Sim consists of 3 PCs, each running Windows-10 (64-bit), with Windows Defender disabled. One is the Server and displays the instrument panel, and the other two are Clients and display external views-- one displays the -90|+90 views on two 24" monitors, and the other displays the -45|0|+45 views on three 24" monitors-- giving a wrap-around 230-degree outside view. Each monitor is driven by a separate output from the video card (in other words, the view is not "stretched" across the monitors). The systems are networked together by OpusFSI (latest version). Each system runs a licensed copy of Prepar3d v2.5.  The only add-ons running on all three systems are OpusFSI (FSIserver on the Server and FSIClient on the two Clients) and FSUIPC4 (both latest versions). In addition, the Server runs SPAD (v5.1). The Server contains 3 add-on aircraft: Carenado C337 SkyMaster, PMDG 737NGX, and PMDG 772LR. The client systems have one add-on aircraft: the WideVieW Dummy.  I have created Custom P3D Camera Views for each client machine using the WideVieW Dummy, and used Opus LiveView Camera to create the "panel" views on the server system.

 

Specs on the PCs follow:

 

Server: i7-5820K (6-core) CPU, ASUS x99-A motherboard, NVIDIA GTX760, 16gig DDR4 Corsair RAM, Thermaltake 750w modular PSU. Overclocked to 4.0 GHz, water-cooled by a custom loop.

-90|+90 Client: i7-3770K CPU, ASUS P8Z77-V LK motherboard, NVIDIA GTX780, 16gig DDR3 G.Skill RAM, Thermaltake 750w modular PSU. Overclocked to 4.2 GHz, water-cooled by Corsair H80.

-45|0|+45 Client:i7-3770K CPU, ASUS P8Z77-V motherboard, NVIDIA GTX780, 16gig DDR3 G.Skill RAM, Thermaltake 750w modular PSU. Overclocked to 4.2 GHz, water-cooled by Corsair H80.

 

Hopefully, that's a complete description.

 

So, here's my issue. When settting up the system, I monitored the Position Update Rate of both clients using the SPY function on the OpusFSI Client. Initial rates for all 3 aircraft (C337, B737, and B777) were approximately the same-- about 116 to 120 updates per second. This resulted in a very smooth motion as seen through the external views, and a maxed-out locked frame rate of 31 fps. I flew the C337 for an hour, and the position update rates remained stable. In the case of the 737 and 777, after about 15 minutes of flying, the rate drops to about 18/sec on the -45|0|+45 client and about 32/sec on the -90|+90 client. I also observe that the rate at which the update rates appear on the SPY screen increases. When the update rate is in the 120/sec range, the interval between update rates appearing on the screen is about 2 seconds... when the update rate drops to 32/sec, the interval is about 0.5 seconds... and when the update rate drops to 18/second, the interval is about 0.25 seconds. At low altitudes, this causes a noticeable "jerkiness" especially on the 90 degree views.

 

I have discussed this effect at length with Stephen at Opus, and he assures me that it is caused by an increased overhead or workload on the client systems. I have used Task Manager and Process Explorer to monitor everything that's running on all 3 systems, and there's nothing out of the ordinary. As I said, Win Defender is disabled, so it's not an antivirus issue. Also, I have run the PCs overclocked and at stock settings, but this didn't make any difference.

 

I ran essentially the same Sim on Windows-7 (64-bit) systems, and never had an issue like this. I'm using the same "tweaks" on the W-10 systems. There are only 3-- Fiber Frame Time Fraction is set to 0.01, Optimize Parts is set to 1, and Bufferpools (Usepools) is set to 0. In NVIDIA Inspector, the only change I have made from the default for P3D is to set Vertical Sync to 1/2 refresh rate.

 

Sorry for all the detail... just trying to give a complete picture.

 

Has anyone experienced this? Solved it?

 

I also posted this in the Prepar3d forum.

 

Thanks.

Henry

[paulyg123 135]

I can't begin to comprehend your set up.  You gotta post a picture if this.