Texture_size_exp and CPU impact?

[TheBoom 31]

After reading about this tweak a few months ago and how it affects VRAM and GPU usage I naturally set it to 10 and forgot about it. 

Noticed with complex aircraft I needed to turn down autogen settings quite a bit to keep frames above 25-30. I assumed it was the higher autogen loading in v4 compared to v3 and older versions so I kept it that way. 

Out of curiousity I decided to fiddle with the terrain size exp tweak and dropped it to 9. I honestly did not expect that much of a difference on CPU but I couldn’t have been more wrong lol. 

The difference between 9 and 10 allowed me to have 1-2 steps in all 3 autogen sliders and maintain the same FPS in dense cities. 

Anyone else noticed this? Or is it a placebo effect I’m seeing?

Do you guys think it’s worth to have higher ground texture resolution and less autogen or vice versa? I know it’s subjective but nonetheless an interesting discussion. 

[Bert Pieke 7,585]

This has been discussed on the LM Prepar3D support forum.

10 is an optional setting that puts a lot of load on the CPU and GPU and is not generally recommended (except at your own risk..)

9 is the default when setting Extended Terrain Textures to "on" in the UI.

8 is the default when setting Extended Terrain Textures to "off" in the UI.

So, unless you want to experiment with 10, there is no need for that line in the config file (at all).

Just use the UI (only).

LM also cautions that conflicting settings in the UI (off) and settings in the config file (9) as an example can cause performance issues... so keep that in mind.

Just to keep things simple, there are three valid settings:

1.  Extended Terrain Textures "off"

2.  Extended Terrain Textures "on"

3.  Extended Terrain Textures "on" combined with a manual tweak to the config file: Texture_size_exp=10

[TheBoom 31]

Oh must have missed that. Thanks. 

Nevertheless I wasn’t aware the load on the CPU would be that significant going from 9-10. I was under the impression it puts more on the GPU but it seems to be doubling the workload on the CPU apart from just using more VRAM on the GPU.