How Beefy of a X86/X64 SBC Do I Need?

[HopWorks]

Greets All!

I am in the middle of a tutorial on setting up a Raspberry Pi 4 (8gb) SBC to act as a ZoneMinder server that would receive 4x1080p RTSP feeds, and serve up a selected monitor periodically through a gigabit switch and router. The end of the tutorial offers caveats on how there "Will be drop-outs" and "it really is a matter of CPU capabilities". The tutorial goes on to recommend using a X86/X64 SBC. So, I want to feed the server 4x RTSP 1080p feeds without hiccups and that number MIGHT increase to 6. The monitor feed will always be one feed only.

So what level of X86/X64 (not sure yet the advantage of 64 bit vs 32 bit) should I look for? Or is my RPI4 with 8gb of ram enough? Does it matter if I use the SD card or external SSD (for the OS, plan to add a SSD for the recorded video)?

Not sure it matters, but each camera I use is either using it's own RPI4 (4gb) as a client, feeding RTSP to the server, or an after-market camera that has all that built in.

I also have a functioning Odroid XU4 but its ram amount is only 2gb. It DOES have a eMMC module at 64gb. I plan to try that and bench performance vs the RPI4 (headless).

I am at my wits-end with this. I know it is possible for my project, and wonder if I should throw more money at it. I also considered using my Core I5 laptop as the server. I just do not want to short-change this project and would rather have a dedicated system.

I am thinking ahead. I have not gotten to the point where I have tested the RPI4 8gb yet. If it works great, this is all moot. But I am running out of time. I depart for my trip a week from Sunday and want a functioning system in my Kia Sorento. So I am thinking ahead at options, and fairly desperate.

Thank you so much for your time!!!