Number of BDCs Necessary

The ratio of workstations to servers in a domain is a way to maintain responsiveness during logging on. More BDCs (also called domain servers) permit more users to log on simultaneously. One BDC can support up to 2,000 user accounts. The server configuration in Table 2.10 is for a 486/66 computer with 32 MB of RAM, running Windows NT Server.

Table 2.10 BDCs per number of user accounts

Number of workstations

Number of BDC servers

10

1

100

1

500

1

1,000

1

2,000

1

5,000

2

10,000

5

20,000

10

30,000

15


It is a good idea to perform the initial setup of all BDCs on site or over high-speed links because each new BDC will need a full synchronization with the PDC. Many companies set up their BDCs at the same site as the PDC and then ship them to their intended locations. This is the most efficient method for sites that have only low-speed or RAS access.