Validate error after performance tuning

[Chas]

I would follow through the same troubleshooting as this first:

Polling just got ~300 % slower

Try ./poller.php -d -h host -m ports or -m sensors, as are the ones with biggest polling times. Then you can check what is taking so much time, if SNMP, MYSQL or RRD. I bet is a disk issue. Whats your disk I/O for librenms?

Run the poller.php on a device, and also check disk IO / available ram and CPU.