Max Regions Purge Per Frame

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I was after a little advice on what settings are available for the "MaxRegiosPurgePerFrame" setting.


Using the fantastic AVSIM guide, i have managed to get a pretty fluid and stable P3d running.


However, i am aware of a small stutter when changing this setting from 4 to 16. 4 causes to much VAS usage, whereas 16 indices the small stutter.


My question is, what are the values available? From what I read, and I maybe wrong, the values to use are 1, 4, 16 or 64.


Is this correct or are there other values that can be used? Ideally A balance between 4 and 16?


Thank you!

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Thats great, I assumed I could only use certain values.


I shall try a figure around 12.

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I have never heard about this. Would you care to elaborate abit about it. What does it do and which section of CFG do it put it.



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Quote from LM :


To reduce stalls was to put a limit on the number of scenery regions purged per frame. This was part of the big updates we made to optimize trees. As you fly around, scenery regions get requested based on distance from the camera. Scenery regions hold model placements, auto-gen, etc.

The terrain mesh/texture data is handled through a totally different system though which relies on the LOD radius. The scenery database loads modes based on your scenery complexity, and makes auto-gen requests based on auto-gen settings, etc.

The regions represent 64km, 16km, 4km, and 1km tiles with 16 children. These are loaded as needed and stay in memory until purged. Because of parent/child dependencies, the system only purges by distance at the 64km level. When a top level region is removed, it then recursively removes its children.

Autogen tree data is stored in 1k cells, so there could be up to 4,096 tiles worth of three placement data to free up. This would cause very noticeable hangs. So, rather than remove all the tiles, we que them up for remove and remove a few every frame.

Originally this was set to something low like 4. We raised it during the last round of memory optimizations to help speed up the process of clearing memory and avoid potential edge cases where fly fast at a low framerate might allocate memory faster than it gets freed.


Summary : Decrease value to reduce long frames (stutters), but VAS usage could increase. Increase value to reduce VAS usage but will increase long frames (stutters).

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