Kerbal Space Program

This bug-report might be considered 2-fold:

[primary]

Semi-persistent framerate drops @ unreasonable maxed-out GPU loads:

I've found heavy (semi-)persistent drops in framerate on moments when GPU-load sometimes seems to get maxed-out in unreasonable circumstances, dropping the framerate all the way from 60 FPS to ~20 FPS. Strangely enough causing a (graphical) context switch (by pressing the Win-button) seems to (temporarily) relieve the problem, reducing the max GPU load and returning the framerate to 'normal' values. However, in-game context switches or just in a matter of time, the problem of max-GPU load seems to return and cause the drop in framerate again.

Odd enough, while trying to record the problem using NVidia's ShadowPlay, it did NOT occur. Somehow ShadowPlay seems to 'prevent' the maxing-out of the GPU-load and hence no drops in framerate occur. This is also why I had to record the videos with a handheld camera.

VIDEO 1: Demonstrates the problem with the maxed-out GPU load (using Process Explorer) and the drops in framerate (and how a context switch sometimes restores it)

https://www.youtube.com/watch?v=vFy3E7L--zI

VIDEO 2: Demonstrates how the problem is 'gone' when running with ShadowPlay recording enabled (also proving the hardware is working properly and is capable), but does show a secondary framerate problem when a plane/rocket is displaying atmospheric effects along it's hull, as described below in [secondary].

https://www.youtube.com/watch?v=O8XjT0m-mPY

[secondary]

Excessive drop in framerate during higher CPU loads when atmospheric effects are visible on the plane's or rockets's hull (framerate drops from 60 to 36). See also video 2 at around 3m30s.

NOTE: Both 32bit and 64bit KSP versions seem to have both problems!!

COPY OF YOUTUBE COMMENTS ON VIDEO PART 1:

I think the videos explain themselves. Unreasonable GPU-loads seem to cause 'persistent' framedrops, which seem to disappear when I force a (graphical) context-switch by pressing the Win-button. A lot of the time, this (temporarily) restored the framerate to original values (usually 60 FPS), however, at the end of the video you can see that my attempts to 'restore' the framerate with a context switch does not seem to work anymore.

Note that this problem occurs in all stages of the game: menus, space center, and during simulations and in both versions (32bit and 64bit).

In Part 2 of this video, you can see me running the game with NVidia ShadowPlay enabled, which somehow seems to be able to 'prevent' the 'persistent' framedrop from happening in the first place. This is also the reason why I had to record the problem with a hand-camera.

NOTE: Running the game properly while recording with NVidia ShadowPlay also proves that my hardware is not malfunctioning, and that it's likely to be a KSP or Unity software problem. Other applications and games run properly.

COPY OF YOUTUBE COMMENTS ON VIDEO PART 2:

While recording with NVidia ShadowPlay, no improper GPU-loads seem to occur and the 'persistent' slow framerates are gone, as shown in this video. This also proves my hardware setup is quite capable of running most of the game @ 60 FPS (except for the part where 'Station One' is visible (there it drops to 34 FPS, but only 22 FPS when GPU-load is maxed out as seen in Part 1).

You would expect running with ShadowPlay to potentially make the persistent framedrop problem worde, but actually, it seems to somehow 'prevent it'.

Besides all this, there is another 'problem' visible in this video. Namely at around 3m30s in this video, you can see CPU load increase when the atmospheric effects are visible on the plane, and framerate drops from 60 to 36... which is quite ridiculous. When the atmospheric effects are gone, the framerate returns to 60.