I read an article a while back about why git is slower on windows than on linux (probably linked from HN, but I can't find it just now) and the TLDR is that it's because the windows filesystem (not just NTFS, but everything around it) has many customization points, and for that reason git will always be slower on windows regardless of the particular underlying FS (as in, adding windows support for, say, ext4 wouldn't fix the problem).