Huge FPS drops when below 8km on Duna

[Vortexian2]

For some reason when as I enter duna's atmosphere with a space plane (any space plane small and large) my fps starts to tank until I reach 8km from the surface then my computer just dies and my fps just drops to almost nothing and makes the game almost unplayable. I have tried this with task manager up and it doesn't seem to be a hardware problem.

I don't think it is mod related (maybe)

Also I have landed on duna before in this via Apollo style craft and there was no lag it seems to only be caused by vessels with wing parts.

Also this doesn't happen on kerbin or Laythe or anywhere else. It is just Duna where this happens.

Please help!

(I have posted this in the modded pc support too because I am not sure if this is mod related or not)

Edited December 18, 2019 by Vortexian2

[Arco123]

We need a log and a mod list. For the bug fixers and stuff. I don't know how to fix it...

[Lisias]

It's a wild guess, but it worths to try.

With the revamp of the planet textures, the VRAM usage increased. Since I play on a Potato since 1.4.0 (and now and then I play 1.2 and 1.3), I'm seeing a regular drop out of the FPS on the same scene as KSP versions evolve, and in my rig I confirmed it's VRAM related - too much textures, and the GPU starts to steal CPU RAM for texture, and now we have both disputing the data bus.

When you fly over a planet, KSP optimises the rendering using a thing called PQS. It's essentially a MIP for objects, telling the 3D engine to use a simpler version of the planet and statics when you are far and using a more.detailed one when you are near.

Since your problem happens exactly at 8Km, I bet it's PQS related due the new Duna textures.

I minimised my problem by lowering the Texture Quality. Set it to the lowest qualify (1/8th) and try it. If the problem disappears, raise the Texture Quality a bit, and try again. Stop when the image is.good enough for you, and rollback one setting if the problem happens again before that.

Edited December 18, 2019 by Lisias
I didn't wrote that way. I swear! My mobile autocomplete is trolling me!

[Vortexian2]

I don't think it is PQS related since I have already set the texture quality to the lowest and it still happened and it happens below 8 km sea level not surface level. I should have said that first.

Also the only mods I have installed are some visual mods (Scatterer, Chatterer, EVE, and SVE) and some ease of life mods (mechjeb, Kerbal Engineer, Joint Reinforcement, Alarm Clock, and Precise Maneuver Node).

I have already tried without all visual mods and there was no difference.

[Vortexian2]

Also I am in 1.7.3 not 1.8.

[Fraktal]

1 hour ago, Vortexian2 said:

Also I am in 1.7.3 not 1.8.

You may want to consider upgrading. 1.8 includes some major performance improvements.

[Lisias]

51 minutes ago, Fraktal said:

You may want to consider upgrading. 1.8 includes some major performance improvements.

As well some regressions and performance degradations.

I have to play using Textures at 1/8th, and this setting makes most icons unreadable. (and even checkboxes! I don't when a checkbox is checked!!!) Even some startup screens are terribly pixelated on my old rig.

Some parts are not behaving as I'm used, and so some crafts are not flying anymore. All the performance enhancements (and yes, it's better on performance!) rendered useless for my current games - I'm waiting 1.8.2 to figure out if I'm stuck on 1.7.3 until I'm bored with my current ganes and decide to start new ones. Since I also upgraded my terribly old MacPotato to a slightly less old one, 1.7.3 is now pretty decent (and the performance gain was bigger than using 1.8 on the old rig).

But, of course, your mileage may vary. I suggest to install KSP1.8.1 separately from your main games and give it a try without mods first, to feel the thing.

[Vortexian2]

I don't know about Macs but I would think it would be better than 5 fps on duna in 1.7.3 and I am in 1.7.3 still because I am working on a career save and I don't know if the save would work on 1.8

[Lisias]

1 hour ago, Vortexian2 said:

I don't know about Macs but I would think it would be better than 5 fps on duna in 1.7.3 and I am in 1.7.3 still because I am working on a career save and I don't know if the save would work on 1.8

Backup everything, update to 1.8 and give it a try without too much expectations There're a lot of nuisances and only a few really bad bugs, but the performance improvements are real - the weakest feature on that Old Potato is the CPU - it was never that fast, but since the security updates from Apple about that Spectre and Meltdown tragedies, my FPS hit the ground.

Interesting enough, KSP 1.3 and older still perform the same. My guess is that as KSP started to explore multi threading more aggressively, that patches from Apple started to bite (as they mitigated the problem by hindering the hyper threading, what rendered my machine with half the workings horses).

The new Physics engine is saving CPU from other places, giving me back some of the performance I lost on that patches. I think I'm getting 3 or 4 additional frames per second - and since I was getting about 5 FPS too, that effectively almost doubled my FPS!

you may prefer to wait KSP 1.8.2 however, it's rumoured that Squad will release a new bug fix for 1.8 before going to 1.9.

Edited December 19, 2019 by Lisias
Hit "Save" too soon.

[Vortexian2]

Quick update! I was going to try 1.8 like how Lisias said but I thought I would try something first. Some more information first, this KSP install I am using is a copy of an old 1.7.3 Steam version which after copied I modded. So, I thought I reinstall my non modded steam version, roll it back to 1.7.3, copy it, install all of my mods from the other one via ckan, move the save over, and try it then. Surprise! This somehow fixed the issue but for some reason my about half of my mods, even though installed just decided to not work. Mods like Mechjeb, distant object enhancements, among others. I think it is because of some save specific data the mods save in them selves in the game data folder as I did not copy them from there to my new install I just downloaded them from ckan again. I will try doing that next but I don't know if that is the issue if I could get some clarification about this first from you guys it would be great! (you can tell I am excited because of exclamation marks and me writing like some one else) 

 

So if some one can help me fix my mods or can fix my other install via the new information it would go a long way!

Also I still don't think is mod related since I have already tried uninstalling most of my mods in my original install and I still went down to 5 fps. 

I think it is install related. If anyone can figure out this problem and can fix it I would give them 20 dollars if I could.

 

[Vortexian2]

I just did some tests and apparently I forgot to test uninstalling real plume on my old install and apparently that fixed the issue. I would really like to use realplume though and uninstalling it apparently disabled my hotkeys for all engines aside from the rapiers. 

So, I am taking this discussion to the realplume forum.

 

Sorry for the inconvenience and thank you for all your help.