Performance issues below 1000 ft AGL / optimisation inquiry.

[Art-J]

Does any of you gentlemen with less than "latest and greatest" hardware notice serious performance degradation of WWII version of Marianas when trying to fly low above terrain?

I recall a couple of posts on the subject and even Reflected commented on it in his recent campaign teaser video, but I wonder what's really taxing GPUs so hard whenever one tries to fly exactly below 1000 ft AGL at any given spot. I don't think it's infractructure, 'cause there's less of it compared to modern version. I was thinking about trees, but even when I got them temporarily replaced with modded ones from Taz (modern Marianas version), there was no improvement. 

My old RTX3070 runs out of VRAM immediately on this map (fair enough with only 8 gigs) and it would be easy to say "VRAM is to blame", BUT... modern version uses up even more VRAM - and it still runs butter smooth compared to WWII one. Same for Nevada low above Vegas.

What gives then? Some lousy LOD transitions? Terrain textures resolution? True, if I switch them to lower setting, the map will run smooth, but again, any other map I own runs smooth with them on "high" , even when textures are spilling over to system RAM.

Let me show how things look on my PC below:

1) First screen shows how my Ctrl PrtsScr graphs on WWII version look like above 1000ft AGL - both are smooth and I can maintain V-synced 60 fps easily.

2) Second screen shows what happens when I get below 1000 ft - frame time becomes jittery and fps goes down the drain, jumping between 45 at best and 25 at worst.

3) 3rd screen shows for comparison how graphs look like on Marianas modern version - VRAM consumption is even higher and yet, the map still runs smooth.

4) 4th screen show my gfx settings.

While we're at it - what does the "T" parameter means in top graph, the one after fps? In WWII version It seems to be about 10 times lower on average compared to other maps, maybe that tells something?

 

[MigratoryBird]

I also remember bad performance on this map flying low level over inland portions.......

....I was of the impression that is was even worse than modern day Marianas.

I have 64 Gb of RAM and 5060 Ti 16GB VRAM .....maybe that helps to know , because VRAM alone does not seem to be the limiting factor here. ( for example I can run Cold War Germany Map flying over Berlin just fine ....)

 

[BJ55]

T: time in seconds from when it started monitoring. Same horrible performance here, above Rota GPU load is 99%, without shadows and using medium textures goes to 80%, changing LOD, time or weather has little to no effect. P-51D takeoff pratice quick mission above Kagman is a little better, with high settings GPU is at 85%... TTI unplayable!

[Holbeach]

I have the same problem, but only with the Corsair. Sudden frame drop to 20fps, same as Falklands.

My cure for this is also the same. Reduce 'Unit Texture' (not 'Terain Texture), to Medium. This gives a minimum smooth 42fps at jungle tree top height. 80 at alt.

 

..

Edited Tuesday at 08:18 AM by Holbeach

[Art-J]

Thanks for the feedback. The problem might be ground-textures related then, although it's not strictly about VRAM usage in itself (?).

I'm puzzled about what the actual culprit is, because these textures do not look THAT much better and more detailed compared to modern Marianas ones. I wonder what their resolution and compression method is. I'm not at home, however, so can't investigate further at the moment.

[peachmonkey]

I tried flying on this map when it was released, and then couple of weeks later after some minor update and the performance is abhorrent on it in VR (4090 with 98003xd).  Haven't touched it since.