How many users can be in a AD LDS group?

Solution 1:

I did not find a valid, clear answer, so wrote some code to create 1 milion users, and add them to a single group.

On a 1vCPU, 2G RAM virtual machine running Windows Server 2008 R2, we found that :

1. AD-LDS has no problem holding that much data.
2. Adding a user to the directory or to the group is done in constant time, regardless of group membership size
3. ADSIEdit has a hard time listing users when the count goes over 5k. It works but the mmc.exe process consume a lot of CPU time and the whole thing slows to a crawl
4. LDP virtual list view works, but you have to tell it what you are looking for. Listing all values is too slow to work
5. Apache Directory Studio was stable and fast, with good support for paging.