Specs should be fine.
The server doesn’t normally have much input into polling time, its normally network latency, how busy the end device is, and the amount of data collected. You can turn off poller modules you don’t need to decrease the time polled.
The polling time will probably be longer on librenms as it provides more information by default. I would test this with one of your devices first.
Unfortunately Librenms cannot currently mix and mash 1 minute + 5 minute polling.
See 1 minute and 5 minute polling on the same server