This is what the service contract states for Fiber customers. This is the link
"For customers served by fiber to the premises technologies, Cox-provided routers/gateways cannot support download and/or upload speeds of more than 940 Mbps per individual compatible device. Customers can reach a total of 2 Gbps via speed test when using multiple compatible devices at the same time. For other network architectures, Cox provided routers/gateways may support up to 2 Gbps download speeds on an individual compatible device."
