That depends on the Motherboard how much RAM it supports. Generally most Consumer Motherboards has a 128 GB RAM capacity.
Some do have 256 GB of Ram Capacity but that depends on the Processor. Many Ryzen Theadripper Motherboards support up to 256 GB of RAM.
As an example only here are ASRock Motherboards that are compatible with your Pro 5750GE: https://www.asrock.com/support/cpu.asp?s=AM4
I believe the ASRock Aqua is their Top of the line X570 Motherboard. It has a maximum RAM capacity of 128GB: https://www.asrock.com/mb/AMD/X570%20AQUA/Specification.asp#Specification
The Ryzen processor won't fit in a Intel Motherboard so you would need to purchase a new AM4 Motherboard and possibly new RAM set that is compatible with the Motherboard and AMD Processor.
Here is Crucial website explaining what Dual Channel Memory is: https://www.crucial.com/articles/about-memory/what-is-dual-channel-memory