Quick note: This is with ALL FSDT Scenery, not just YVR. I'm posting it here because I fly in and out of YVR quite often. If this has been covered/solved in the past, please link a forum post here.
Anywho, this has been an ongoing issue for quite some time and I cannot for the life of me figure it out. When I am maybe 15-20nm from YVR in any direction or even just flying over top of it, (when in range where the flight sim thinks it needs to be loaded in) my sim will pause for about 15 seconds, then continue, then pause for 10 seconds and then finally continue. As you can imagine this is infuriating in some cases, because sometimes I am in turbulence and it has caused me to lose complete control of my aircraft.
This problem is very persistent since it is still there after a full reinstall of my sim (this has been on all versions of FSX and P3D that I have used), complete OS reinstall (even when I upgraded from Windows 7 to Windows 10), reinstall of the scenery, updated the Addon Manager, updated the scenery, updated my graphics card, updated literally everything that could require an update. This even happens when there are NO other addons in P3D, just YVR (or any other FSDT Scenery that I have tested on a clean reinstalled)
My specs: Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz, 16GB Ram, 1TB HDD, 250GB SSD and NVIDIA GTX970 (latest drive as of right now, 417.71)
Addons used on a daily (not including addon scenery as I have too many to list lol): P3D v4.3, PMDG 737NGX + 6/700, 777/F + 300ER, 747QOTSII, FSLabs A320 + 319, Majestic Q400, PTA (latest version) AS for P3D, Avilasoft EFB v2.0, Navigraph Charts, ProjectFly, Vpilot, FlyChrono, PFPX, Chaseplane.
This issue occurs regardless if P3D is the only thing running on my PC.