Hi Arun,
The number of flows will be limited by the ACL hardware on the switch, as this is used to implement the flows.
The X440 has a relatively small amount of ACL hardware, with only 4 slices that can each contain 256 rules. These slices are subject to other constraints, including the type of match conditions in the ACL (or flow in the case of Openflow). You can find a more detailed explanation of this in the EXOS User Guide, under the
ACL Slices and Rules section.
-Brandon