RAM Requirement for Backup Exec 2012 Deduplication

The minimum amount of RAM is 8 GB, which supports up to 5 TB of deduplicated data.

Note: This minimum requirement is in addition to the minimum requirements for Backup Exec.

For more than 5 TB of data, use the following calculation to determine the required amount of RAM:

1.5 GB x N, where N equals the number of TB of storage in the deduplicated volume. Up to 32 TB of data is supported.

Example: Use the following equation to calculate the required amount of RAM for 10 TB of data:

1.5 x 10 = 15 GB RAM

Source: Best practices for Backup Exec 2012 Deduplication Option