IP camera surveillance

I'm trying to cost the replacement of an analogue cctv system (42 cameras) with an IP solution that is scalable to around 100 cameras. My beef is with NVR's are these even needed given that IP camera streams are already encoded can't the streams be dumped straight to disk nas or server? I have a spare high end server and am keen to utilise this, realistically how many cameras could be recorded with one box and any recommendations on software. I expect to utilise H.265 cameras to reduce bandwidth and capacity

NVR = Network Video Recorder?

This is a pretty specific technical question, yes, camera streams can be recorded straight to a NAS, but how many, I haven't the faintest. Can't google answer this?

The difference with NVR's is they are dedicated to the task, and not as likely to have glitches and freezes during the encoding, when compared to a NAS or other server...

you COULD record to a NAS, but it would have to be configured in such a way as to capture each camera stream individually (from each IP) and save to an individual folder per camera, with a unique filename per camera, per day etc.... if you're fine playing around with a NAS, changing it's OS/Firmware and setting it up to do said task, provided it's network capabilities are up to the task, then it is certainly an option...

an NVR, you plug in, configure and go.... - you can always have the NVR backup to the NAS on a regular basis as well though!

as for software, I have only ever used iSpy on Windows (other than cameras own packaged software)

Any NAS that can't record streaming video from a few concurrent sources has got something wrong with it.

But 100 sources, well, I'd suggest that the network might be the bottleneck before disk IO.

I'm just staggered that someone would want to monitor and record 24/7 a hundred cameras...

But then I know nothing....

it certainly doesn't sound like a domestic pursuit so would be better dealt with by professionals who have experience of supporting such high numbers of cameras.