@Joshua Bloom - you can turn off all Windows updates and all
Blue Iris updates and then it is essentially a better NVR!
And you do not need to buy a new PC. A member here just last week found a refurbished 4th generation for less than $150USD that came with Win10 PRO, 16GB RAM, and a 1TB drive. Most of us purchase refurbished PCs that come off a business lease. A lot cheaper.
And a 4th generation is plenty now with the substream option. A member here is running 50 cameras on his 4th generation at sub 40% CPU
Have you tried an NVR for playback - most of them suck. I can literally in less than a minute watch any activity from overnight on
Blue Iris. It takes longer than that just to log into my NVR. And then playback is atrocious - even more so if you need to watch back for several days to find out when that car parked on the street was hit.
And common practice is to match brands of cameras with the NVR, so you may find a mix-match of cameras do not work properly with an NVR.
The ability to add more cameras and from different brands and do 3rd party add-ons if you desire I believe puts the favor into Blue Iris.
Most NVRs will cap the bitrate you use. And limit the resolution of the camera. As long as your computer can handle it, BI can accept whatever bitrate and resolution the camera is capable of.
An NVR is a watered down computer with an underpowered CPU that is running 24/7...I still am running an NVR that feeds cams to my BI computer. The NVR is pulling more power than the BI computer...
I have had whatever the NVR operating system is running on go out. TWICE. Got to buy a whole new NVR - TWICE
I have had the ethernet port go out on an NVR. Got to buy a whole new NVR.
i had the HDMI port go out on an NVR. Got to buy a whole new NVR.
Most I ever got was 2.5 years. The only working part was the HDD that I simply moved from the old NVR to the new one. I got to the point of realizing that an NVR is simply a stripped down computer, so I went to BI and never looked back. I got tired of buying a whole new unit.
So in my BI Computer, at least if the SSD goes out, I can just replace it. If the ethernet card goes out, I can just replace it. If the HDMI port goes out, I can just replace it. etc.
Personally I gave up on NVRs because I have found them to be clunky and a struggle to review clips and if a component goes out like the internet port, then you are stuck buying a new NVR whereas a computer part goes out and you replace just that component. I went to BI on a dedicated machine and haven't looked back.
Keep in mind that not all NVRs are created equal - look at bandwidth - a cheap one is usually limited to 80Mbps total bandwidth for all the cameras and limits cams to 4096 bitrate, so once you look at an NVR that can pass a higher bandwidth, the dedicated computer and
Blue Iris was cheaper in my case. Pros and Cons to each and many people on here run NVRs successfully.
You will spend more on a capable NVR than you would a BI/PC combo...