Lower texture size and especially texture quality settings.
High texture quality settings lead to high VRAM demands - too high for my 560GTX (1GB). For a more detailed and technical explanation and pointers to solving these kinds of problems and general awesomeness read especially @BitVenom 's posts below.
just bought the game. Instead of having fun, I was battling with strange framedrops and the graphics options.
I get good frame rates on high settings one time. After restarting the game, I get very low framerates with laggy mouse control. This may also happen after loading a save. The graphics options do not influence this. I can also have good frame rates after restarting the campaign but bad frame rates in the same session after loading a save state. I can also have a cut scene (e.g. Agnus dei flyby) with low frame rates and the game afterwards may have a good frame rate.
I start the game HW:R 1, put most of the graphics options to max (8k textures, textures on 9, vsync on, shadows on, lighting on max, HDR on, AA on 4) and start mission 1 of the campaign. Agnus dei plays, flyby of mothership - I am impressed, I really like this, everything is smooth
I play until you have to test the salvage corvette… and my fighters accidentally kill the target for the corvette. Mission control tells me it will send another target. Target never arrives (probably a bug). Mission incompletable. I close the game and do something else.
Later: I start the game again, start mission 1 again, Agnus Dei starts playing , huge framedrops during the flyby, the mouse control is very choppy, game is unplayable (Windows task manager: CPU at 45-50%, GPU temp normal, CPU core temps slightly above normal values for my system 60-65C but still ok).
I play around with the options and nothing helps, (vsync on&off, shadows on&off, AA none, 2 ,4 8). I restart the PC. Restart the game, everything works again. Campaign mission one 1… bla… everything works. In order to test if everything really works now, I close the game again and restart it, and load mission 1 (from a savestate), again low framerate and choppy mouse control.
I will play around with it a bit but I hope someone here can help. Thanks a lot for your help.
Edit: Restarting the pc does not always help - so no virus or other stuff running in the background. Anti virus program on and off tested, makes no difference.
Maybe certain graphic options (like vsync or shadows) need a restart of the game or reload of the map?
Edit: Steam or Homeworld keeps on changing the game’s language from English to system default which is very strange - I had to change it back 3 times already.
Edit: Off to new try… Quit game, start game, restart mission 1 Campaign , Agnus Dei flyby still choppy, so I skip it via the ESC key , BUT the game is completely stable with high settings (Vsync on, AA4x, shadows on etc., 8k textures on 9). I go back to main menu and load the a save from the choppy last time . Game is choppy again. I don’t get this…
P.S.: The bug in mission one which renders it incompletable (see above) may also need to be adressed.
i5 3570k, 8 gb RAM, GTX 560, onboard sound, game installed on SSD