No, a CPU backplate is not required.
No, a CPU backplate is not required.
The backplate includes screw holes for attaching your accessories. Without mounts, you can't secure anything in place.
It varies based on the socket type and H100i version you have. For Intel LGA 775, 115x, or 1200 sockets, you require the backplate to secure the CPU block. Are you purchasing a new unit or using an existing one? If it's brand new, ensure it comes fully assembled with all components intact. Return it to the retailer for proper installation.
Which model of the H100i do you own? What components are missing from your parts list? You're missing the stand-offs. If you're using an Intel socket, it's backplate → stand-offs → CPU block → thumbscrews. Without the essential parts, the CPU water block won't secure properly to the CPU or motherboard at all.
You own a 1151 socket and have all the necessary components except the standoffs.
Are the mounting points identical to those found on motherboards? You have surplus units available.
I have all the components except the standoffs. It’s possible to function without them. You could simply use a nut and tighten it manually.
Sure, placing a plastic washer between the screws could be a good idea for added security.