performance impact of branch in GIT

Question

I have heard conflicting statements about the impact of branching in git. Let's say we have 100 feature branches that are all stored in a remote repo, would that affect performance (CPU/network) in a noticeable way ? How about 1000? 100,000 branches? In other words how does git scale with regards to number of branches?

Answer 1

Remember that git branches are not copies of the files, they are simply pointers to commits. So thinking about the two extremes that this allows, you could have 100,000 pointers (branches) all referring to the same commit. Or you could have 100k branches each referring to a different commit. Thus a repository of 100k commits.
Branch lookup and commit checkout times are bound by filesystem and disk performance. Checkouts might slow down in a repository with a lot of files/commits. But the branch objects themselves are very lightweight.