Hacker News Reader

Comment by conductr | Hacker News Reader

I’m not familiar with inner workings, but simply moving files feels odd in Windows compared to macOS. If it’s a big lift in terms of data size or file/folder counts it’s most obvious but it feels like Windows literally copies the files into memory, then rewrites them on disk or something similar that has results in negative performance and a long running cut/copy/paste dialog box. I’ve had some of these run for hours on decent hardware (SSD, etc) for what I consider small datasets (couple GB). It’s been a major Windows gripe of mine for years now.

Meanwhile macOS appears to just change an internal link to the data that’s already written on disk. As such, it’s usually so very fast compared to Windows.

View on HN

Windows File Explorer does a lot of extra work to get a sense of file sizes and other metadata to try to keep the UI looking fresh/interesting/useful to someone watching the job in real time.

If you need to seriously move/copy lots of files or lots of data in Windows it is generally a good idea to use shell commands. Robocopy [1], especially, is one of the strongest tools you can learn on Windows. (It gets very close to being Windows' native rsync.)

[1] https://learn.microsoft.com/en-us/windows-server/administrat...

Windows does literally copy (parts of) files into memory. More precisely it's Windows Defender Real-Time Protection. It's a real menace when you're dealing with a lot of small files, e.g. node_modules.

Windows Explorer is also slow for an unknown reason.

Doing file operations through the API with Real-Time Protection turned off is several orders of magnitude faster in the case of small files. It's crazy stuff.

A lot of this depends on whether you're crossing devices. If you think of drive letters as mount points it may make more sense - if you're moving between mountable filesystems obviously a move has to be a copy-then-delete; if you're remaining on the same filesystem a move can typically be a rewriting of indexing information only with very limited data rewriting.

One other thing that can be an issue particularly on NTFS with ACLs is that moving files typically retains their ownership and permissions, while copying files typically inherits the ownership and permissions of the destination. This can bite you if as an administrator you're moving data from one user's account to another because a move will leave the original owner still owning the files.

That's likely to be due to the NTFS file system. Another piece of legacy Windows drags along

Eh, with moving files on Windows in the same security context it is 'generally' pretty fast on the same drive.... Are you sure you didn't paste in a directory that is setting new security permissions on all files?

Been a while since I looked at the details, but Explorer's file management is generally slow compared to what you can do with the actual Win32 APIs.

Reply on news.ycombinator.com