Cafeen

You may want to look into the OpenGL option if the 64-bit isn't working properly. Dropped my usage from ~3.5GB to ~2.0GB during active play. There are some potential quirks with some visuals, but if the 64-bit thing isn't working to open up your memory space, reducing the footprint would be an alternative. It also sounds like your exe file may be named KSP.exe.exe? (The 'KSP.exe_Data' part, since normally it's KSP_Data') This may be something to look into as well. Make sure that you're viewing file extensions in explorer and double-check for an extra '.exe'.

One thing to keep in mind with parts mods is that you don't have to use ALL the parts. For example, in my latest setup, I've removed (flat out deleted from the Parts folder) most of B9 and KW Rocketry. I've kept the B9 flat RCS tanks, the B9 Aerobrakes, the B9 utility lights, and the engines from KW. Everything else was removed (and the internals for the B9 cockpits, and various extra stuff that I didn't need.) This can greatly reduce the footprint of those parts heavy mods. I'd also look into the various procedural parts mods (Fairings, you already have listed, but also wings and "parts"). These mods can take the place of loading several other individual parts, as well as reduce overall part count on the final ships (reducing physics-induced lag and potentially increasing stability).

Been messing with OpenGL all weekend (and I think a bit of last week too) after giving up on getting 64 to work nicely with my setup (system and mods). Cut the memory usage in half upon startup and reduced memory related crashes to 0 (down from 1 every 20-30 minutes or so, depending on what I was doing). Textures look the same, though I lost one of my EVE settings somewhere in my tweaking (I again have the white horizon...maybe when I dropped RSPC?). Checked via launching the exe directly rather than through Steam. ~3.1GB usage via DX, ~1.7GB usage via OpenGL. Mods Installed (at least partially, I do tend to edit the mods a touch to fit what I need, either removing parts that I don't use or writing a patch to update/edit something using Module Manager (e.g. Interstellar's science equipment which only half works.)) Toolbar Active Texture Management B9 (Flat RCS tanks, Aerobrakes, and Omni Lights only) Distant Object Enhancement DMagic Orbital Science (with Universal Storage pieces removed) Editor Extensions Enhanced Nav Ball Environmental Visual Enhancements (with Astronomer's pack) Firespitter (removed Bi-Plane and Oblong fuselage parts) Hooligan Labs - Airships KAS KSO KSPX - I think I may have dropped some parts out of here too KW Rocketry MechJeb2 Hot Rockets Near Future - Electrical, Propulsion, Solar Final Frontier Panda Jager Labs Part Highlighter Procedural Wings Procedural Fairings RLA_Stockalike - LV-T5 small and NERVA small only SCANsat Science Alert Mk2 Cockpit internals Texture Replacer TAC Fuel Balancer Kerbal Alarm Clock KSP Alternate Resource Panel Tweakable Everything KSP Interstellar