Can an i3 be sufficient?

I had an old samsung 4 bnc camera setup for years and it did its job.
Recently upgraded to 8 ReoLink 4K POE cameras and put 256gb and 512gb microSD cards in. That is not enough space!!!!

So I have 2 options:
1. buy reolink dvr and just run that OR
2. Build a PC and install BlueIris


I have already bought blueiris so we are good there.

i have spare parts laying around and I can whip this up but wondering if it is worth it.

parts needed:
* Case

Parts on Hand:
MSI Z690-A DDR4 ATX...

Can an i3 be sufficient?