Only use an external drive if it is an eSATA. if it is USB it will not keep up. I would suggest not using this computer as The "T" means the CPU is designed to use less power while also having less performance than the standard chips without any letters. With
Blue Iris and the computer running 24/7, you will have issues.
At that price you quoted, you can find an acceptable computer. A 4th generation would be fine for 4 cameras. Someone here is running 50 cameras with a 4th generation just fine.
What is your intended goal and purpose of the cameras - overview, identify, watch wildlife, etc?
Those cameras are not an ideal MP/sensor ratio! And one camera cannot be the see all, be all camera. A 8MP on a 1/2.7" sensor needs times the light of the 2MP on the same sensor. There is not enough light back there for it to work well at night. A 2MP camera on that same sensor will kick this 8MP camera all night long.
It is simple LOL do not chase MP - do not buy a 4MP camera that is anything smaller than a 1/1.8" sensor. Do not buy a 2MP camera that is anything smaller than a 1/2.8" sensor. Do not buy a 4K (8MP) camera on anything smaller than a 1/1.2" sensor. Unfortunately, most 4k cams are on the same sensor as a 2MP and thus the 2MP will kick its butt all night long as the 4k will need 4 times the light than the 2MP... 4k will do very poor at night unless you have stadium quality lighting (well a lot of lighting LOL).
To identify someone with the 2.8mm lens that is popular, someone would have to be within 13 feet of the camera, but realistically within 10 feet after you dial it in to your settings.
My neighbor was bragging to me how he only needed his four 2.8mm fixed lens cams to see his entire property and the street and his whole backyard. His car was sitting in the driveway practically touching the garage door and his video quality was useless to ID the perp not even 10 feet away.
Here are my general distance recommendations, but switch out the Dahua 5442 series camera to the equivalent 2MP on the 1/2.8" sensor or equivalent Hikvision works as well.
- 5442 fixed lens 2.8mm - anything within 10 feet of camera OR as an overview camera
- 5442 ZE - varifocal - distances up to 40-50 feet (personally I wouldn't go past the 30 foot range but I like things closer)
- 5442 Z4E - anything up to 80-100 feet (personally I wouldn't go past 60 feet but I like things closer)
- 5241-Z12E - anything from 80 feet to almost 200 feet (personally I wouldn't go past 150 feet because I like things closer)
- 5241-Z12E - for a license plate cam that you would angle up the street to get plates up to about 175 feet away, or up to 220 with additional IR.
- 49225 PTZ - great PTZ and in conjunction with an NVR or Blue Iris and the cameras above that you can use as spotter cams to point the PTZ to the correct location to compliment the fixed cams.
You need to get the correct camera for the area trying to be covered. A 2.8mm to IDENTIFY someone 40 feet away is the wrong camera regardless of how good the camera is. A 2.8mm camera to IDENTIFY someone within 10 feet is a good choice OR it is an overview camera to see something happened but not be able to identify who.
Main keys are you can't locate the camera too high (not on the 2nd story or above 7 feet high unless it is for overview and not Identification purposes) or chase MP and you need to get the correct camera for the area trying to be covered. A 2.8mm to IDENTIFY someone 40 feet away is the wrong camera regardless of how good the camera is. A 2.8mm camera to IDENTIFY someone within 10 feet is a good choice OR it is an overview camera to see something happened but not be able to identify who. Also, do not chase marketing phrases like ColorVu and Full Color and the like - all cameras need light - simple physics...