Motion detection - ZoneMinder vs ONVIF budget camera

[mattj]

I'm looking for opinions on how well motion detection works on budget (under $150, such as this one) ONVIF cameas in general, vs. how well motion detection works on ZoneMinder for 1920p resolutions.

I'm trying to educate myself about IP cameras before buying them, and what I'm learning is that ONVIF cameras detect motion in the camera, then notify the NVR of the motion event... in theory. Some references online make me think that budget cameras (under about $150) might skimp on the motion detection performance to keep costs down. I also read that ZoneMinder does not support this part of the ONVIF protocol, and does its own motion detection by decoding and analyzing each frame. I assume this means that ZoneMiner is good at motion detection, but how much CPU horsepower does it take for ZoneMinder to detect motion on a 1920p camera at 15fps? Is it reasonable to expect ZoneMinder and a 3.1GHz i7 processor to reliably detect motion from (12) 1920p streams at 15fps/each?

[bbunge]

I would not consider that a budget camera. It has more resolution than you will need! 640x480 is plenty for most and my 17 camera system works well at 320x240.
Bb