FPS Drop due to FAR "Debug", And FarConfig.cfg not properly responding to edit #155
Description
I recently installed RP-1 for the first time, using the express install route, which uses FAR version 0.16.1.2. I added a few of the optional mods as well as a few minor QOL mods. (My modlist is attached at the bottom)
I noticed some REALLY bad lag in a few gameplay sessions, and could not figure out what was going on. I noticed the lag would get worse the longer a game session went on. At first I wondered if it was RAM or GPU issues but it was not. For reference, I have a core i7-13700k, 32GB ram, and a GTX 4060.
I'll skip the whole "what I tried to debug" stuff, but all the usual, asking people on the RP-1 discord for help. I do not know exactly WHAT is causing the issue, except that it revolves around FAR Debug.
Side Note 1: "Prefer GPU" is selected by default when you open FAR using the toolbar button (in flight) and then select the "FAR Debug" menu.
The issue seems heavily tied to how many separate craft are spawned. In my test, I created a simple rocket that had 16 SRBs radially attached with radial decouplers.
The basic steps I will take with each flight are as follows:
- Start via the "simulate" button from the VAB
- Once craft is loaded in, change camera angle to be straight down onto the craft, for consistency of camera. Note FPS (FPS is measured via the time control mod window)
- Change Far Debug from "Prefer GPU" to "disabled" Note FPS again
- Launch craft, making sure to hit the staging where all 16 boosters get separated. Wait a few secs Revert to launch.
- Repeat 2-4
First launch: FPS ~124. After changing to "disabled": ~126 (remember, these are the FPS values while the craft is just sitting on the launch pad)
do the launching, separating.
Second launch: FPS 115 -> 127
Third launch: 114->126
(Here I switched the boosters to be slightly larger to see if it would have a different impact)
Fourth launch
Fifth launch 111->128
Sixth launch (or seventh, i might have missed one) 108->126
Ninth launch 102 -> 128.
Now is the point where the fun happens. I will check my FPS after launching craft on this ninth launch: about 80 when SRBs are boosting, and back to about 110 after radially decoupling (this is with the "disabled" setting, not the prefer-gpu)
Next launch, I will KEEP the prefer-GPU and pay attention to FPS as we fly: 47 in flight, 25 after decoupling. i managed to quickly change to "disabled" on the debug setting and FPS immediately went up to 110.
Next launch, keeping prefer-GPU set. (and remember, this is the default. I have not changed any settings in FAR, I have not checked any of the radio buttons. I'm just playing the game "as normal"). Again, 50ish in flight, 24ish FPS after decoupling.
A few more launches with very similar results, but each time the FPS drops are a bit more, seeing closer to 40 in flight, sometimes dipping below 20 to 19 or 18 after decoupling.
At this point the evidence is incredibly clear that SOMETHING fishy is going on. FPS dropping down to the 20s after the radial decoupling, but if I try a launch with the "Prefer GPU" turned to "Disabled", instead I get 100 FPS with only a single frame that drops below 100.
Issue #1 So clearly FAR is creating some sort of garbage over time, and setting the Debug to "disabled" somehow makes this garbage not matter, but the default setting is "prefer GPU" and therefore is problematic.
Issue #2 I attempted to modify FARConfig (after this test) so that it would default to none, unfortunately this does not work, and it continues to default to "prefer GPU" on EVERY LAUNCH. This is incredibly frustrating as it means the longer I play the game, the more it means I have to literally open FAR and change debugger to disabled on every single launch.
(here is a pic of what I set the .cfg file to, to no effect).
Thank you for looking into this and any and all help you can provide!
KSPLog.zip EDIT: Now this is a zip so that it could just be attached normally
COMPLETELY forgot to attach my ksp.log the first time, so I did a similar experiment, this time just grabbed my light-sat rocket, strapped 20 boosters radially to it, launched a couple times. After 3 launches, with "prefer GPU" still set, it was down to EIGHT FPS. Yes, 8. After decoupling. change prefer GPU-disabled and it went up to 98! Here's the log: (if there's another better way to upload, let me know. I can't seem to find a good solution for huge text files)
https://jumpshare.com/s/SK1mx7aCBjrKigxb8R15