How many files can you put in a Windows folder without a noticable performance degradation?

Solution 1:

Assuming NTFS here, in which case the technical limit is around 4 billion files. And until you go over 10s of thousands per directory you really should not worry too much.

Note however that programs like Explorer suffer much sooner than 10s of thousands, because they try to access all files in a given directory to get meta-data, etc.

Solution 2:

Opening a file won't be very slow regardless of how many files you have in a folder. What certainly is going to kill you is enumerating files in that folder. So taking a look at the contents of that folder with Explorer, Far, dir, Get-ChildItem, whatever.

That being said, I have around 2.5k files and folders in my temp folder and display is instantaneous, so that's apparently still a small number.

ETA: Ok, just tried it, 10000 files in a folder take around one second to open that folder in Far, this and 20000 files don't even matter in Explorer.