50% real throughput for all PFDM PMP links

I am testing three separate PMP450 deployments. One with 430 SMs, one with a mix of 430 and 450 SMs, and one with only 450 SMs.

The built-in link capacity tests shows impressive speeds. with an 80% downlink, I am seeing minimally 75Mbps/16Mbps downlink/uplink on 450 SMs and 38Mbps/8Mbps down/up on 430 SMs.

However, running a number of speed tests, most of which were run using iperf with 4-8 streams of UDP, the most I see on a 450SM is 38Mbps down and the most I see on a 430SM is 20Mbps down. It would seem that the 430 and 450 PMP systems are limited by design. The upload seems unaffected.

In stark contrast, all PMP100 series be them 900, 2.4, or 5 all produce 100% of the throughput indicated by their respective link capacity test. And for perhaps a closer comparison, the PTP230, which is essentially two 430SMs, indicate 40Mbps/10Mbps down/up and actually produces 40Mbps in all tests.

Can anyone explain what’s going on with PMP OFDM radios?

There are some packet processing limitations on the SM side of PMP 430 and PMP 450 systems.

We are indeed making improvements to this in an upcoming software release. Look for updates via our “Open Beta” software, which should be coming in the next week or so.

Also, I would encourage you to use the “newer” forums, located here:


These are far more actively monitored and responded to… (these forums are only being kept around for reference now).

With the newest 15.0.3 firmware I am seeing realword 450sm unlimited getting maxed out around 50mb.  Is this about what we can expect out of the old sm design until we get the new sm that are hopefully coming out soon?  sm speedtest always look great even showing above 100mb speeds with 30mhz channels. Obviously they could never go over 100mb do to the ethernet port, but can Cambium please confirm that about 50mb down is the best it will do because of the processing power of the old design?  Do the 450D work better, we have never tested them?  We have hundreds of 450sm and they are all in bridge mode, no nat.  Thanks, Craig.