git/Documentation/config/checkout.txt

checkout.defaultRemote::
	When you run `git checkout <something>`
	or `git switch <something>` and only have one
	remote, it may implicitly fall back on checking out and
	tracking e.g. `origin/<something>`. This stops working as soon
	as you have more than one remote with a `<something>`
	reference. This setting allows for setting the name of a
	preferred remote that should always win when it comes to
	disambiguation. The typical use-case is to set this to
	`origin`.
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Currently this is used by linkgit:git-switch[1] and
linkgit:git-checkout[1] when `git checkout <something>`
or `git switch <something>`
will checkout the `<something>` branch on another remote,
and by linkgit:git-worktree[1] when `git worktree add` refers to a
remote branch. This setting might be used for other checkout-like
commands or functionality in the future.

checkout.guess::
	Provides the default value for the `--guess` or `--no-guess`
	option in `git checkout` and `git switch`. See
	linkgit:git-switch[1] and linkgit:git-checkout[1].

checkout.workers::
	The number of parallel workers to use when updating the working tree.
	The default is one, i.e. sequential execution. If set to a value less
	than one, Git will use as many workers as the number of logical cores
	available. This setting and `checkout.thresholdForParallelism` affect
	all commands that perform checkout. E.g. checkout, clone, reset,
	sparse-checkout, etc.
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Note: Parallel checkout usually delivers better performance for repositories
located on SSDs or over NFS. For repositories on spinning disks and/or machines
with a small number of cores, the default sequential checkout often performs
better. The size and compression level of a repository might also influence how
well the parallel version performs.

checkout.thresholdForParallelism::
	When running parallel checkout with a small number of files, the cost
	of subprocess spawning and inter-process communication might outweigh
	the parallelization gains. This setting allows you to define the minimum
	number of files for which parallel checkout should be attempted. The
	default is 100.