I am running a receiver for years now and put my antenna outside now.
Yesterday I had 278 total aircraft but only a message rate of 1250 msg/s.
I reach this rate with an aircraft count of 150 and up it is constant.
I tried different sticks (orange, blue and airnav) and different filters (first fa filter and a cavity filter) , all with nearly same result. Also tried different gain settings and looked at strong signals.
So I think it is maximum rate here because there are also mode ac signals around. If I activate --modeac I will get around 2200-2300 msg/s
I do not feed mlat results back to my Dump1090 client.
Had same experience with my indoor raspberry station.
So that could be too much traffic on that frequency or is it too much for a raspberry? I am located in north west part of Germany.