Tepnox

Ok. Got some new testing. It is possible to reproduce this bug just by start and stopping on the runway. I tested this with the F/A-18 on the runway. Accelerated to about 100 knots and came to a full stop. Repeated this step and every time, the load of the GPU shrinks and so do the FPS. This is because of the increasing LUA CPU value. It took me 7 start-stop attempts to bring the performance down to 30 FPS and the LUA CPU Value was at a 70% level. This is the maximum, the performance will drop. Tested this on the F-5. Same issue, but the performance drops were a little bit lower, so it took some more start-stop attempts to melt down the FPS. Here is the video: These were the ingame settings I used: The extreme after 7 to 8 attempts looks like this: FPS are down to 30 FPS, my GPU load only is at 24% and the LUA CPU Value is at 70%. Performance drops no further after these attempts. So, clearly a bug in the engine itself it seems.

Hi there. I was investigating this kind of trouble you run into. I couldn't figure, how there was no real bottlenecking but also lacking performance after landing. Reason for this is possibly a bug in the rendering engine of DCS World itself with the LUA CPU Usage value. Normally, this value hovers around 1-5 % when starting the mission (on ground and air) and just flying around. But after landing, the value for LUA CPU Usage spikes depending on the flying module up to 40% (on the F-18 for example) and it stays this way! I made a video, it shows the F-18 starting on an empty NTTR-Map on the runway with a short round and landing. What you will see is, after landing on the runway, the LUA CPU Usage Value gets to around 40% in the Hornet. The load on the GPU drops significantly and thereby the FPS. There is no bottlenecking at all (not CPU not GPU wise). For this test setting, all shadows are disabled (because they seem to have also a negative impact on the engine calculation and degrading the GPU loadout - especially the case, the more static airplanes are parked around you). I locked the FPS with Rivatuner to 120fps and normally, this is the way, I like to fly around. Watch for yourself: For best viewing results, please use the 1440p quality for this video. (The text is very small in the analysis window). The worst thing is, the LUA CPU Usage stays at this 40% after landing. Even switching to the F-5 and back to an unpowered F-18 doesn't help. To fix this back to normal, you have to leave the mission and load it up again. I think, most people are not aware of this bug, because of gaming around 60fps. As you can see in the end, the FPS are barely around this value so many people wont notice the background high-load at all. This is clearly an issue for people trying to fly in VR and for people who want to fly in much smoother high FPS. Hope, this helps you out and gives a little more insight of what seems to be the problem. This is clearly reproduceable. You can see, there is clearly something off, when watching the frametime line (values in ms - milliseconds). The frametime gives an impression of how fluid the frames are delivered. In the beginning, it is nearly flat with some minor spikes, because the GPU hits the limit and sometimes couldn't deliver 120fps but that is ok, as long as the load of the GPU is around 99%. The ideal way to play games in general, is to bottlenecking the GPU (load should be mostly around 99% so the GPU pushes the maximum available frames) - the CPU should always have some headroom and no usage around 99%. But having low CPU-usage AND low GPU-usage with lowered frames is always a bad sign as you can see in the frametime line after landing. You could see, that the engine is struggling hard in the backround and fighting itself for some reason.