I have a solution to my problem with IXEG with fluctuations FPS at regular intervals( for example 45-33-45-33-45-31 every 7-10 seconds)
In the PC I have, among other things: i7 3770K OC 4.6 Ghz and Asus Strix GTX 980Ti 6GB. So, with this did not have a problem with IXEG normally 40-55 FPS for example on KSEA (of course depending on the setting buildings, roads, traffic, etc.)
I've tried several older drivers for NVidia GTX 980 - without success.
I ended up at 368.29
I did some things, and maybe together that solved my problem or maybe it is all resolved only one change in the setting NVidia.
All those things as elimination of the X-Plane from antivirus software and others tips I had long before the release IXEG.
I used these plugins: PluginAdmin,AutoGate, CustomSBDatarefs004,Gizmo64, PythonInterface, RealWeatherConnector, SilverLining (SkyMaxxPro v3.2), SoundMaxx, X-Life, XPUIPC.
I use FSGRW as weather injector.
I removed prior to testing the World Traffic plugin and already currently I not use it.
I changed the number of objects, shadows, traffic, etc., and I stayed in this setting (attached picture 1)
Then I tried to shut down in the scenery.ini all files W2XP (SCENERY_PACK_DISABLED Custom Scenery / 4.w2xp_Africa / America / Europe etc)
It probably has no direct impact on IXEG but it has to do with setting the density of buildings and thus CPU load) But as I write above, most of the time I had no problem to have a high FPS.
And now maybe the main thing that's solved my problem . Changes in the NVidia panel settings/Manage 3D Settings (Second and third image. I am sorry. Panel is in my native language)
I changed: Ambient Occlusion - Performance
Optimizing Threads - off Triple Buffering - off
Vertical Sync - Adaptive (half the refresh rate of the monitor) I have Samsung 27" 60Hz
In the previous GPU (GTX 680) after changing drivers (I can not remember the version) Were more profitable and better with setting vertical sync - off.
That's why I used this setting (vertical sync- off) with GTX 980. Now I use what is written in the blue font.
I now have a stable 30 FPS and perfectly smooth flight simulation without fluctuation FPS. There is still a bit of a problem when changing clouds or weather, but it is probably a problem SDK X-Plane
If after this setting will be the mouse slow.Turn off in the mouse settings "shadow indicator" and increase the speed indicators.
Okay. I think, it is about everything I wanted to write. Perhaps this helps someone. Sorry for my english.
Just a little note 1: In me PC these changes will take effect after the restart not only X-Plane but the restart the entire computer.
Just a little note 2: Before running X-Plane I use this utility from Asus "Asus GPU Tweak II" section "Gaming Booster" (The image 4)