Kerbal Space Program

whatever this is, please get it sorted! I can't fly planes in KSP at all due to massive lag when the horizon is in view!

I had two weird moments now since I opened this issue, one was in high Minmus orbit (as in just entered it's SoI) where the FPS dropped too quite a lot for no reason.

The other was where I had my usual launchpad lag, especially the bigger drop when looking at the buildings, but then when I launched and reached maybe 1km it ran so damn smooth that I thought I was outside of Kerbol.
No matter where I looked around, horizon, buildings, ocean, it was so smooth I never had that before except with a maybe 5 part test ship, but this was with a nearly 150 part ship.

So no idea what's going on there but it could run very smooth, but it seems something is hindering it.

Sorry I forgot the hardware info, GTX 660M with 326.80 beta driver on Win7 x64 HP. Here's also a DxDiag https://dl.dropboxusercontent.com/u/59546146/DxDiag.txt

Here's a gallery of spots I tested looking at including the FPS I got with my default settings (first screen).

http://imgur.com/a/5UMIn

I then gradually went down with the settings not getting an improvement until I just went down to outright minimum. Then it became better.
When I started reverting settings one by one to my defaults I was surprised that it didn't went down when I turned the Terrain Quality back up again but the Render Quality (which is a factor for shadows).

I then reverted to my settings again and turned Render Quality to minimum and it was nearly as smooth as total minimum, barely a different FPS wise with the cap at 60. Only at a few spots more than on total minimum did it drop below 60.

I then tried the opposite and took total minimum with Render Quality Good and it was nearly as "bad" as my default settings.

Given Render Quality is related to shadows it's maybe calculating a lot of shadows you wouldn't even notice for their distance or something like that.

Also with total minimum and Render Quality on max. the only time I'm getting more than 30 FPS is when I'm looking flat over the surface of Kerbin, or straight down without water in the view. As soon as water gets in the view it's nearly instantly down to 30 FPS.

There's also another FPS weirdness I'm having: sometimes the Mun mainmenu screen with the Kerbal and the crashed rocket is slow (30 FPS), but if I'd tab out and back into the game it's instantly fine and smooth again, same goes for the Space Center and Launchpad, sometimes it's slow and if I'd tab out and in again it's smooth again.

I found a workaround posted here. - http://forum.kerbalspaceprogram.com/threads/51042-Looking-to-the-horizon-FPS-Drop
As described in the forum post, this fps drop is greatly affected by the Ocean maxSubdivision value.

I can run the game with every setting maxed out, and force high antialiasing, etc. values in my gfx drivers... as long as I don't look at the planet from orbit or the horizon while on the ground. Setting maxSubdivision=2 For KerbinOcean clears it up on Kerbin.

This happened with older nvidia drivers as well, but I've installed the latest.

GLX version: 1.4
OpenGL version string: 4.4.0 NVIDIA 331.20
OpenGL shading language version string: 4.40 NVIDIA via Cg compiler

Let me know if any other info is needed.

I started to get the weird low FPS problem that get's fixed from tabbing out and in again now everywhere after any scene change.

start the game and get to main menu: 30 fps, tab out and in again 60 fps
load the save and get to the space center: same
get into the VAB: 60 fps, until I open the window for loading a craft: 30 fps, after loading it 30 fps, after tabbing out and in again, more than 30 fps (I have some rather big crafts so it varies whenever it manages to reach 60, the point is the fps become here more too)
put the thing on the launch pad: 30 fps when I'm lucky, after tabbing out and in again and not looking at either the buildings or the water: way more fps except for the really big crafts

This is all with an unmodded KSP so it shouldn't be a mod's fault but I guess certain mods can make it worse because I once had fine fps after fixing them and was driving over the mun with a rover and another one came into loading distance and then my fps took a nosedive again.
And as expected did the tabbing fix that again.

I don't know what's wrong there but having to tab out and in again after EVERY scene change is really going on my nerves now.

I updated the DxDiag to reflect my current drivers. KSP version is now obviously 0.23.

Also don't get this wrong, these problem with looking at the planet (or the KSC buildings) at the wrong angle causing a huge fps drop is STILL present, it's a seperate problem than the one with the tabbing. The tabbing just fixes the base fps.

Another thing I noticed is that both fps problems are worst in fullscreen, in windowmode I get way more fps in both cases.
The tab problem becomes differently problematic there though, instead of having lower fps am I having nothing but a white screen with cyan bits where the shadows are AND the whole thing is flipped upside down.
I need to minimize the game and bring it back up to fix that.

And since the question will come up, my driver's pretty recent, I think I updated it two weeks ago or less. But I'll see if there's a more recent anyways and see if anything changes.