Warm Start

Kerbal Space Program starts in less than half the time, because what it works out afresh at every start is kept from the last one: the expansions' files unpacked, the textures converted, the small bundles' descriptions, the parts' drag cubes.

For Kerbal Space Program 1.12.x. Needs Keystone, a separate download (on SpaceDock): this mod does not load without it.

Install

Copy the WarmStart folder from the download into your KSP's GameData, beside Keystone. The first start after that is as slow as ever, and a minute of work goes on in the background at its main menu. From the second start on it is fast.

Good to know

• Measured: to the main menu in 21 s instead of 55 on a Mac, and in 18 s instead of 47 on Windows 11.
• It takes about a gigabyte of disk (GameData/WarmStart/PluginData; deleting that folder loses only the time to make it again) and no memory.
• After a mod is added, updated or taken out, ModuleManager makes the game work out every part's drag cubes again (half a minute for a thousand parts). From 0.3.0 the cubes of every part that has not changed are handed back: 15 s of part compiling came down to 3 s here, with 480 parts.
• With the Harmony mod (not needed), the game's look-ups of models, pictures and sounds go by a table instead of a walk through every one: a tenth off a start with thousands of parts. That is the one part that changes the game's code; it checks itself against the game's own and has a switch. Without Harmony none of the game's code is changed.
• With KSP Community Fixes installed, which loads the game its own faster way, Warm Start does nothing: use one or the other.
• Its page in the Keystone window (the keystone button on the game's toolbar, or Alt-K; Option-K on a Mac) has a switch for each part, and says how long the start took and which mods the seconds went to.

Works on

Windows 11 and Mac: measured (what 0.3.0 adds, on the Mac only so far). Linux: never run (it is plain C#, with nothing of one system's in it).

More: the long description (everything in full, and what was measured on each system) and the rest of the wiki.

Licence

CC BY 4.0: use it, change it and pass it on as you like, as long as you credit Ishiaki and link back here.