I am in the same boat. The shadow from our flag waving in the wind triggers our front door alert most of the day. I would like to find a POE outdoor motion sensor that can send a signal over ethernet for BI, but have yet to find one...
I bought my IPC-HDBW4431R-ZS from "visualexpert" on ebay. A little higher cost but I get them in about a week. They offer a discount for higher quantities.
I have no doubt that direct to disk will help. I run BI that way on my little 3-camera home system.
I was just curious to see if the computer was able to keep up with that many 1080p cameras within reason. I am about to start on a 20ish camera system for work and the PC has similar specs. I...