Performance considerations

General

The larger the combined bandwidth of all your sdr and the more recorders you have defined the higher your system requirement will be.

Multiple Dongles

One way to reduce system load is to have several sdr with smaller bandwidths just on the frequencies needed, reducing monitored empty space in between. eg 1 dongle 2.5 Mhz bandwidth to monitor 2 frequencies 2Mhz apart vs 2 dongle each with 250Khz bandwidth

Reduced Signal Strength

A drawback you may hit when running multiple dongles is that every time you split your input antenna feed its signal strength will be reduced. So depending on your situation you might be better off with a more powerful computer rather than multiple dongles. Another way around this could be a higher gain antenna or directional antenna, multiple antennas or some form of signal amplification either at the mast head or the splitter but im not sure how the later would go.

Conventional system (not trunked)

Currently I found that if you add a conventional P25 system (and possibly the same for analog conventional) to a source it will add a dedicated recorder (separate from digitalRecorders/analogRecorders setting) to the sources bandwidth, which is always 'recording'. The squelch setting determines if a recording is saving data into wav or closing it. As mentioned performance will be affected by the size of the bandwidth source that the conventional system is added too. It seems to almost double your cpu usage just by adding 1 conventional p25 to an existing source that may also setup for a trunked system. Much more that say just adding one more digital recorder to that trunk system. So if CPU is and issue and signal strength is not, you could be better off putting your conventional system/s on separate dongles with only 250Khz.