Not your case. And depends on your use case.
IlTossico
Not x86. I think this answer all questions.
That's a nice heater! And a very good door stop. Nice catch.
Get a Synology NAS. A 4 bay if you have money, avoid the one with ARM CPU, get one with an Intel CPU.
You didn't say where you live and what budget you have. What solution do you want to plan, what HW etc. So I assume you live in Europe, amazon.de, going shuking, you would need 10x18TB drives for 292€ each, total 2920€. Then you can arrange it on RAID 5 and get 162TB, RAID 6 and get 144TB, or unRaid with double parity and get 144TB.
I just Google on amazon.de and do some basic math. It didn't take too much.
That's a good way to kill a disk. Don't use NTFS and you are fine. Go for Btrfs and similar.
Do you plan having VMs or only Containers? Because Plex, alla ARR stuff and NVR can work on containers. In that case the i3 is extremely overkill too, but if you plan to run a lot of VMs, the i5 of course have more core.
In terms of power consumption, both idle around 25W (generic system with no GPU and Idling HDD), the i5 would peak more, but depend on the usage, generally server idle 99% of the time.
TDP doesn't mean Power Consumption for Intel, but is related to Thermal Dissipation. The i3 would consume the same as i5 idling, because of C-state and the ability to almost shut off the unused cores, then on peak power, having more cores and frequency, mean more power consumption, but peak mean burst of 1 second at max.
I regret not having enough money for everything i want.
My NAS build is perfect for my need, and i think it's perfect for most of us, i'm sure there are tons of people that take my suggestion and take some hints from them.
The only real regret i have, is having just 8 GB of ram, for folder caching, 16GB would be better, but i can upgrade, so no problem.
The, of course there is possibility for improve, like ECC, IPMI, better case, bigger drives etc, but those things cost too.
If someone have the capability of troubleshooting and DIY, this remains the best solution for money and performance. Prebuilt are good mostly for company and people that don't want too many problems.
Sorry, i don't understand.
You have a switch, right? Just connect everything to the switch and everything would talk with everything. I don't see the problem.
Do you really need 42U? Can you sell it and get a smaller one?
However, humidity is a big problem.
The DS1821 runs with Ryzen, so no transcoding capability at all. Anyway, most Intel solutions sell on those prebuilt NAS, don't have good performance, mostly enough for the basic Nas function, and mostly old stuff, without all codec support. You need an Intel CPU, one with integrated iGPU, capable of Quickl Sink.
If you need transcoding power, better go DIY. To give you a perspective, an i5 8400 can transcode around 4/5 4K video at the same time. As 1080p, we are over 20+ at the same time. That's the UHD730 power.
RPI zero? Without Ethernet ports? How? Just that is enough of a deal. Without thinking about the cpu power and the fact that pfsense, the free version, doesn't work on arm.