# Server Sizing - Using the Server Specification Calculator

The Server Specification Calculator can be used to estimate hardware requirements for VIAVI GigaFlow.

## Contents |

## Server Requirements

To begin using the calculator, select the number of routers on the network (*D*) and the maximum estimated total number of flows per second (*F* s^{-1}).

## Inputs and Outputs

In the Inputs and Outputs table, the calculator will display the required write MB per second [MB s^{-1}] and write IOP per second [MB s^{-1}]. The formulas used to calculate these figures are displayed. These are derived from experiment.

## Memory

In the Memory table, the calculator displays the RAM and cores required. The total hourly, daily, weekly, monthly, quarterly and yearly total data size is shown in the grayed out boxes. The RAM requirement is based on the estimate that 4 GB is required for the operating system and that each router (device) requires 50 MB RAM for standard operation.

## Storage Required

The Storage Required table displays the storage requirement for the original inputs but also lets you enter new inputs, i.e. total flows per second (*F* s^{-1}) and the number of days storage required. Click the re-calculate button if you enter new input values. For example, if the total number of flows per second (*F* s^{-1}) is 1,000, and the number of days' storage required is 1 day, then clicking the re-calculate will give 21.6 GB.

## Storage Available

The Storage Available table displays how many days it will take to fill up a disk of a given size based on the flow rate. For example, if the total number of flows per second (*F* s^{-1}) is 1,000, and the total storage available is 8,000 GB, then clicking re-calculate will give 370 days.

## More Detail

See Server Sizing for more detail about these calculations.