# Datacenter Placement and Data Transfer Costs

When running a multi-DC ScyllaDB Cloud cluster, data is replicated across
datacenters. The cost of that replication depends on where the datacenters
are placed relative to each other and to your application.

## Same-Region Placement

Placing datacenters within the same cloud region as your application minimizes
data transfer costs. Traffic between nodes in the same region is typically
billed at intra-region rates, which are lower than cross-region rates.

## Cross-Region Replication

If your architecture requires datacenters in different regions — for example,
for geographic redundancy or to serve users in multiple locations — replication
traffic will cross region boundaries. This incurs cross-region data transfer
charges from your cloud provider.

To reduce the impact:

* Use [Local Quorum consistency](https://cloud.docs.scylladb.com/stable/use-scylladb/index.md) for reads and
  writes where possible. This avoids cross-DC coordination on every request
  and limits cross-region traffic to background replication only.
* Add only as many datacenters as your availability and latency requirements
  demand. Each additional datacenter multiplies replication traffic.

For instructions on adding a datacenter, see [Adding a Datacenter](https://cloud.docs.scylladb.com/stable/operate/add-dc.md).