Comcast has begun rolling out another speed increase for its broadband customers subscribed to its Performance tier.

The free upgrade, which began March 1, raises downstream speeds from 50 to 70Mbps. The speed boost is likely to gradually spread across Comcast’s nationwide footprint, but this month the new speeds are available to residential customers in:

• Oregon
• Washington State
• Colorado
• Utah
• Houston
• Tucson, Ariz.

Comcast is notifying customers with older modems they will need to get a new one to take advantage of the faster speeds.