I agree that for this size of network AD is definitely not something you want to deal with unless you want to learn how it works.

However, I’m not sure it really increases attack vectors to have it running, outside of the fact that it’s a new network service on the LAN. The out of the box default configuration is not bad these days, security-wise

There are a few things that determine the amount of RAM your PC can handle.

Simplest is the amount of slots on the Mobo. It’s hard to put extra RAM into a machine if there is nowhere to plug it in.

Next is the motherboard limitation. This is mostly based on the type of RAM it takes. DDR4 has a maximum size of 64GB per DIMM and DDR5 maxes out at 512GB per DIMM

Finally and most crucially is the CPU. CPUs have onboard memory controllers these days and they can only handle the amount of RAM that they can address. This value changes from CPU to CPU so you’ll want to check the specs for the model you have.

If you go over the supported amount, the PC will likely just fail to POST and never boot. If it does boot it will just ignore the extra RAM and never actually use it.

It’s a lot cheaper than getting an EE to design you a more efficient bespoke solution.

Yep, exactly.

If you can buy 10 Pis for the cost of one real PLC, and the only downtime you have if it fails is the time to swap the board and boot the machine back up it’s a no-brainer solution.

I mean, the cold reality is that they developed and released a perfect piece of hardware for industrial automation and sold it for pennies in comparison to other industrial computer boards.

Industry will always have deeper pockets than hobbyists.

I can’t say anything about US cities, but they are all over the place in Canadian cities(or at least they are where I live)