Maximum RAM Maximum CPUs
Edition 32-bit 64-bit 32-bit 64-bit
Windows XP Professional 4 GB 128 GB 2 2
Windows Server 2003 Standard Edition 4 GB 32 GB 4 4
Windows Server 2003 Enterprise Edition 64 GB 1 TB 8 8
Windows Server 2003 Datacenter Edition 128 GB 1 TB 32 64

Table 1 Tabulating 64-Bit Power
Use this table to determine the new limitations of X64. As you'll see, there is not much change in the number of supported processors. The real gain is with memory access. Note that even though the operating system can access this processing power, the actual access you gain will depend on the hardware platform you are running.