2x RasPi3 or 1x RasPi4 better for Home Assistant + Rhasspy

I am currently happy with Home Assistant Operating System running on a RasPi 3B, with 3 TP-Link energy monitored power points and 3 LIFX light bulbs. I am renting, so don’t imagine adding many more devices.
I have however realised that controlling HA from a smartphone or even a dedicated tablet will be less than ideal; the Goodle/Alexa demo received good WAF :wink:
Rhasspy seems to a better approach for voice control, and I am awaiting a ReSpeaker 4 Mic Array for Raspberry Pi.

I note that Rhasspy can be installed as a Hass.io add-on; or on its own RasPi 2, 3 or 4. So, I am wondering whether it would be better to install Home Assistant, Rhasspy and Node Red all on my Raspberry Pi 4 4GB (thinking inter-process communication will be faster than between machines), or would I be better off splitting the functionality between Raspberry Pis (effectively providing more concurrent processing threads) ?

I have installed HA, NR…about 23 containers including Rhasspy in RPI 4 - they run perfectly fine. My RAM usage is ~30% and CPU rarely goes above 30% when using rhasspy, otherwise idles in 8-13% ransge

Thanks for that. I remember in the 1980’s hearing of a university using a network of PDP-11’s to analyze speech, so assumed that it would still be very processor intensive.
From your comment, I think I’ll try adding Rhasspy to HA on my RasPi 3B, and see how that goes, first. Easy to install on the RasPi 4 later :wink: