F4U - Terrible frame rate in VR

[Pappy_Gunn]

Is this happeneing to others?  I play VR, and my "ask" for frame rates is 80 per second.  I have half a dozen warbirds, 3 helos, and a bunch of jets.  I get 80 fps steady with all of them.  Playing Reflected campaigns in the P-47, I still get 80 fps.  With the Corsair, I get about 15-20 just standing still in either Mariana WW2 or Detling.  Same setup with a P-47, I get 80.  On the Essex, I get about 40 fps in the Corsair tops, usually less.  This make the aircraft unplayable in VR.  Thank you for your attention on this matter...

[javelina1]

post your rig specs Pappy.  

[GTFreeFlyer]

No different for me compared to others 

[westr]

8 hours ago, Pappy_Gunn said:

Is this happeneing to others?  I play VR, and my "ask" for frame rates is 80 per second.  I have half a dozen warbirds, 3 helos, and a bunch of jets.  I get 80 fps steady with all of them.  Playing Reflected campaigns in the P-47, I still get 80 fps.  With the Corsair, I get about 15-20 just standing still in either Mariana WW2 or Detling.  Same setup with a P-47, I get 80.  On the Essex, I get about 40 fps in the Corsair tops, usually less.  This make the aircraft unplayable in VR.  Thank you for your attention on this matter...

Set Marianas ground textures to low. I notice little difference in terms of visual standards in VR but see huge performance gain. This however changes depending on maps so I use different graphics profiles for the maps I use which is a bit of a pain but that’s how it is. 

[Art-J]

Both Corsair and WWII Marianas are just fps-hungry modules, especially Corsair in VRAM department. Using them together is the worst combo.

I've hit a wall of my old 3070 performance with these, even though I'm a 1440p pancake user. I can either fly "lighter" modules (P-51D for example) over WWII Marianas, or Corsair over modern Marianas butter smooth for the most part, but WWII Marianas AND Corsair combo just kills my fps when flying low over palm trees.

[peachmonkey]

Marianas ww2 map isn't optimized as the modern one, at least for VR it's very heavy even for my 9800x3d cpu with 4090.  I quit flying it until ED updates the textures...

[-Rudel-]

Have you tried any of the 2K cockpit livery options too?

[dcval]

On 7/26/2025 at 9:35 AM, Pappy_Gunn said:

Is this happeneing to others?  I play VR, and my "ask" for frame rates is 80 per second.  I have half a dozen warbirds, 3 helos, and a bunch of jets.  I get 80 fps steady with all of them.  Playing Reflected campaigns in the P-47, I still get 80 fps.  With the Corsair, I get about 15-20 just standing still in either Mariana WW2 or Detling.  Same setup with a P-47, I get 80.  On the Essex, I get about 40 fps in the Corsair tops, usually less.  This make the aircraft unplayable in VR.  Thank you for your attention on this matter...

Yep, I set the canopy reflection to 0, and everything went Ok. It seems the F4U uses too much reflection mapping everywhere in the cockpit. Try it and tell us ...

[nephilimborn]

On 7/27/2025 at 5:18 PM, dcval said:

Yep, I set the canopy reflection to 0, and everything went Ok. It seems the F4U uses too much reflection mapping everywhere in the cockpit. Try it and tell us ...

Experiencing the same performance issues - also do not have these issues with the p47 over the same terrain, conditions, units etc. The canopy reflection helped alot - THANK YOU, however i still experience wild and frequent spikes when units are resolved near the F4U and over any map (excepting caucuses). The dcs log file has thousands of these entries and they seem to correspond to when the spikes occur

2025-08-04 15:22:38.030 WARNING LOG (11288): 1 duplicate message(s) skipped.
2025-08-04 15:22:38.030 INFO    F4U_FlightModel (Main): Damage, element[98] : 1.000000

Later today will try the following and see if things improve

1. disable_write_log = true in autoexec (if IO issue related) - probably unlikely?
2. test with invincibility on (if damage system is triggering crazy unnecessary? or collision model artifact when F4U is near AI, certain terrain, or carrier, etc?)
3. cockpit global Illum off (i think i already have that off but will check)

[Update] None of the above made any difference...

Edited August 6 by nephilimborn
Update on tests

[Mr_sukebe]

Please take a scan here:

 

[nephilimborn]

19 hours ago, Mr_sukebe said:

Please take a scan here:

 

Thank you @Mr_sukebe, i have previously leveraged this post in the past to assist with VR perf challenges and found it very helpful . I am pretty confident that i have all bases covered with my DCS environment and as such I am convinced this is a DCS module introduced behaviour. I can sim with this module as long i don't get near a map that has units (carrier based operations over the water only), for any other warbird scenarios i am back to the p47 as the performance spike stutters (every second) with the F4U is not workable.

[Mr_sukebe]

My thread includes comments about how to identify bottlenecks, eg VRAM being saturated.  In your case, what’s the issue?

[Pappy_Gunn]

I will try turning cockpit reflections off, thank you.  For others, note that I said this is not limited to the Mariana map (although it is the worse).  It alsho happens on the Normandy map, on the ground, with zero other aircraft.  Only for the F4U, all other aircraft OK.

AMD Ryzen 9 7950X3D, X870 Gaming Plus Motherboard, NVIDIA GeForce RTX 3080 Ti, 128 GB RAM.  Meta QUest 3.

[Pappy_Gunn]

Tried it with cockpit global illumination turned off and it helped.  Still only getting 40 fps versus 80 with P47.  Spikes here and there, but at least it's flyable.  

[Qcumber]

The F4-U is definitely more demanding. I can still maintain 72 FPS on most maps but it has a higher GPU load. I need to do a direct comparison of frametimes with other modules. 

[nephilimborn]

i feel this is a simulation main thread performance issue with this module;  its damage model and collision logic seems to be running wild for nearby  objects (non-static map objects); introducing frametime cpu bottlenecks. My GPU is not stressed at all during these spikes, however the main thread pool is. The log file is littered with thousands of damage model info messages. F4U’s FM/damage? model seems to scale badly when nearby dynamic assets.

Edited 24 minutes ago by nephilimborn