Low Frames Issue (No Mods Installed)

[Silverfishstix]

Since the 1.0.5 update, I have been getting some framerate issues that haven't occurred before. I have no mods that could be causing this issue. I was wondering if I could fix this in any way.

[diomedea]

KSP includes more features with every release, and often improves the accuracy of existing ones. But sure that has a price, more CPU cycles required to handle all this. Low framerate can be either caused by the physics (the engine takes too long to complete complex computations) or by graphics (complex scene to be rendered). Given what changed in 1.0.5, I would bet the issue is with physics.

There is no magical solution to this issue. Some improvement can be expected by changing the "Max Physics Delta-Time per Frame" setting, a best value for your system may be found.

Real improvements are expected with KSP 1.1, where multithreaded physics should be a reality thanks to the new Unity 5 engine.

But in case you noticed some signs of downgrade (relative to 1.0.4) that could be tied to a specific problem, more info would be needed to determine what is the cause: could be a routine is taking excessively long and could be optimized to perform better thanks to the info you may report.

In that case, would be helpful if you uploaded a specific game situation (a savegame when the issues occur) and provided directions to recreate the situation from that savegame (e.g. enter flight mode with a specific vessel, do some specific action with that vessel). Could be useful to also provide your settings (upload your settings.cfg) and output.log (from KSP_Data), provide info about your system (CPU, RAM), could upload a pic of the KSP screen when framerate issues are occurring with the debug menu open (Alt-F12) and the performance tab selected.

[MLWostal]

As I too am having issues with stuttering since 1.04 and now, with 1.05 being even worse, what should I be doing with Max Physics? Should it be lowered or increased? I am unsure just what this setting does and would prefer to know what to expect with the change.

I'm running a AMD II x4 955 @ 3,2ghz, 8 gigs ram, GTX 750 TI on windows 7 prof. KSP 1.01 was fine but since 1.04, my system is showing frame rate issues especially when in atmosphere or approaching a planet. I've dropped my textures and display settings down really low but those settings have very little impact on the stuttering. The time indicator is almost always yellow if I have anything but the simplest of vessels. I'm to the point that the fun of KSP is being replaced with frustration. Please, any help would be appreciated.

[diomedea]

As I too am having issues with stuttering since 1.04 and now, with 1.05 being even worse, what should I be doing with Max Physics? Should it be lowered or increased? I am unsure just what this setting does and would prefer to know what to expect with the change.

I'm running a AMD II x4 955 @ 3,2ghz, 8 gigs ram, GTX 750 TI on windows 7 prof. KSP 1.01 was fine but since 1.04, my system is showing frame rate issues especially when in atmosphere or approaching a planet. I've dropped my textures and display settings down really low but those settings have very little impact on the stuttering. The time indicator is almost always yellow if I have anything but the simplest of vessels. I'm to the point that the fun of KSP is being replaced with frustration. Please, any help would be appreciated.

Can't provide a sure recipe about best settings, each system and install (if not game situation) may require different ones. I would actually check the performance tab (from Debug menu) to find the FPS ingame, and if too close to the Minimum FPS, would try tweaking.

What I can certainly tell, the "Max Delta-Time per Frame" controls the worst case condition.

Normally KSP should complete all physics calculations within the time for the next frame to display. Let me say that is when the time indicator is green. The actual FPS shown on the performance tab would then be higher than the minimum.

When running out of time, KSP starts to delay the next frames. That setting tells how long the interval between frames can arrive. Of course the longer the interval, the less accurate and less responsive KSP becomes. Less accurate makes KSP choppier, less responsive means any input is affected by lag. I'd be safe to tell then the time indicator shows yellow. The actual FPS drops to the minimum, and the minimum FPS = 1 / "Max Delta-Time per Frame".

In the extreme, calculations require even more time than the Max Delta-Time allows. I am of the idea (but can't confirm without seeing the code) frames may actually be skipped at that point. Red time indicator should be representative of this situation.

But to stay on the simple, a lower Max Delta-Time setting (e.g. 0.03 s) makes for a very smooth, accurate, but also slow-motion run. It could be best when flying a complex vessel with lots of parts, to avoid physics forces to get too large and bring spontaneous disassembly. Certainly the indicator would be almost always in the yellow.

A higher Max Delta-Time setting (like 0.12 s) allows large intervals, so KSP is less accurate and responsive, but also would run faster. As the Minimum FPS is then allowed to be lower, a green time indicator would more probably show; however the number of actual FPS doesn't increase, only the time between each frame.

Then, the setting is more affecting our experience with the game, rather than solving framerate issues. We can't exclude physics routines in KSP, that would be a way to reduce the time taken to perform calculations. Some parts are excluded from physics interaction (their config has "PhysicsSignificance = 1") to diminish the number of parts requiring calculations. The scenery, beyond graphics rendering, always requires CPU time, so limiting scenery elements is always useful. Deleting debris helps, showing data (either from stock KSP windows or add-ons) requires more CPU time.

The real improvement remains the ability to use the full power of modern CPU, that Unity5 should allow with multithreaded physics.

[cantab]

If you didn't copy over your old settings file, there's a good chance that's behind the problem. I used to use similar hardware to MLWostal and one of the big ones was the aerodynamic effects - anything other than minimal would noticeably hurt performance.

[MLWostal]

Thanks for the quick reply. Will be trying the aerodynamic change tonight. Sure hope it helps as a new system is out of the question. Just blew my money repairing this one.