For my scene I have mostly only used LOD 0 for all foliage and trees, but I have set this in the meshes and how I imported them, not in any MRQ settings, so the foliage should be the same in the High resolution screen shot and the MRQ render.
The way the RAM increases in MRQ seems to be as the MRQ is collecting samples it is gradually filling the Ram up, leading to almost full Ram usage for 900 samples, but crashing due to running out of ram if I increase the samples.
Using EXR format seems to make the problem worse, but I haven’t compared if JPEG is better then PNG.
I am using a blueprint actor in the level to set console variables so I can swap between working lighting and rendering settings and either path or ray traced with one click.
I could open the project and post up all my console variables and settings if that would help.
my system is Ryzen 3700x, 64gb RAM and RTX 3090.
thanks,
Mike