Number of Users and Groups Affects SAM Size of Domain

• Microsoft Windows NT Workstation version 3.5
• Microsoft Windows NT Server version 3.5

This article discusses domain limitations in terms of the numbers of users in a group. The way groups within a domain are set up affects the size of the security accounts manager (SAM) database.

The table below represents general guidelines, which assumes that the computer function only as Domain Controller (DC), and no other major Windows NT operations are occurring on the server (it's not being used as a file server, Remote Access server, SQL server, or SNA server). All values are in megabytes (MB). This also assumes the pagefile is at least 250 MB.

Number    SAM      Registry       PagedPool     CPU Needed   Pagefile   RAM
of Users  Size     Size           Size          Needed       Size

  3000      5      25 (default)   50 (default)  486DX/33        32      16
  7500     10      25 (default)   50 (default)  486DX/66        64      32
10,000     15      25 (default)   50 (default)  P, M, or A      96      48
15,000     20      30             75            P, M, or A     128      64
20,000     30      50            100            P, M, or A     256     128
30,000     45      75            128            P, M, or A     332     166
40,000     60     102            128            SMP            394     197
50,000     75     102            128            SMP            512     256

NOTE: The processor type is relatively unimportant in relation to the number of users supported on a domain controller. Processor type is more important when considering client authentication, and when domain controllers are used for more than one purpose. For large domain operations, Microsoft recommends that you do not use the machine for anything else.