Hi all, first post here. Across 3 different graphics cards (GTX 980, Intel Arc A770 16gb and now my RTX 4090) Ive noticed that the fighter jets from Indiafoxtecho (F35s) Heatblur (F14) and Top Mach (F-22A) all produce a low pressure water vapor “bloom” on the top of the aircraft model when pulling a high G turn/climb etc. When this effect appears, my frames drop in half according to the Steam FPS counter. You can really see it too, no counter needed to know that the FPS has plummeted.
The 980 was a stuttering low FPS mess, the A770 actually faired decently but definitely a 1080P card at the mercy of the single threaded CPU and the RTX 4090 is… well… a monster. Universally though, as soon as the bloom appears the frames drop by half.
My specs: 5800X3D, X570 mobo, 32GB RAM, M.2 SSDs, RTX 4090. Currently displaying in 1080P, but Ive got the render scaling set to max at 4k. Working on getting a 4K monitor or TV to natively display at 4K.
Are the vapor effects CPU bound or GPU bound? If CPU bound, that makes sense and boy MSFS 2024 cant get here fast enough. I find it a bit hard to think its GPU bound since the same issue has followed from the Intel to the 4090.
Quick update: Issue still occurs, but I reenabled HAGS and turned Frame Generation back on using TAA for my AA. Min FPS now about 50 as opposed to 25-30.
I’m guessing there are some serious physics calculations going on when you see vapor effects. I have seen them in the few flights I’ve taken in my CJS Rafale, and they’re really cool. I haven’t paid attention to how performance was affected. I don’t have frame gen (lowly 3090 Ti peasant here…) but I’ll definitely check it.
As to whether those calculations are handled by the CPU or GPU, I’m also guessing it’s 100% CPU, as I don’t think the sim code takes advantage at all of the Phys-X capability of GPU’s. I could be wrong.
I routinely monitor CPU and GPU load using HWMonitor during flight. I can also check those parameters when pulling G’s in the Rafale. Surely the vapor effects are a fairly simple visual thing - it’s the physics that tasks the system.
Hi all. Well, after much more research I was able to find a “solution” aparrently a Windows setting was causing the sim to drop frames with water vapor effects. Im not sure exactly how, but it was recommended that you disable it in the BIOS if possible and of course in Windows.
Navigate to your system devices and scroll down to the H’s and youll see High Precision Event Timer. Right click and disable. Dont bother deleting it, it will always come back active. Disabling it keeps it off.
ASUS motherboards do NOT have the feature to turn it off at the BIOS level, but so far Windows lever disabling has cleared up the issue.
With Frame Generation and scaled to 4k with 1080P output, Im about 100 fps via the Steam in game counter. When I make a sharp turn and get the vapor puff, the fps indicates its still dropping but only down to like 65… annoying but vastly better.
The sim also feels much much smoother, absolutely how you expect it to perform with a high end GPU.
I still wonder how MSFS24 will perform in this regard, if the physics calcs alone can be offloaded to a few threads. I can only imagine how much better and more performance everyone will get who have a multi-core hyper threaded CPU.
Long ago I disabled HPET and replaced it with ISLC, which will monitor and clear the memory standby list according to the configured options parameter you set. Basically the good things that HPET does, but much more ‘intelligently.’