The maximum throughput achievable by a PMP/PTP 450/450i/450m device depends on its configuration parameters: duty cycle, range, number of contention symbols, frame length. Changing these inputs changes the number of data symbols used in the downlink and uplink direction.
Given a set of configuration parameters, how do you know how many data symbols are available in the downlink and uplink, and what is the largest throughput you can expect? The PMP/PTP 450/450i/450m Throughput calculator has the answer: https://support.cambiumnetworks.com/files/colocationtool/
In this example, the AP is configured with a 75% duty cycle, 20 MHz channel BW, 5 mile range, 6 contention slots and 2.5 ms frame lenght. Each frame has 58 DL data symbols and 19 UL data symbols. This translates into a throughput of 95 Mbps (DL)+31.1 Mbps (UL) = 126.1 Mbps (total). Note that this throughput refers to 8x modulation (256QAM MIMO-B), and it scales down proportionally if lower modulation modes are used.
What is the largest throughput that can be achieved? For example, using a 40 MHz channel and a 5 ms frame, the total throughput is as high as 308 Mbps!
Note that for the PMP 450m AP, the tool gives the maximum throughput in non MU-MIMO mode. The throughput in MU-MIMO mode will be higher, and it depends on the multiplexing gain (which in turn depends on the average group size).