Some dual-channel motherboards include four slots to accommodate additional expansion cards or high-speed components.
Some dual-channel motherboards include four slots to accommodate additional expansion cards or high-speed components.
Exceeding 4GB isn't really helpful when targeting a 32-bit OS such as XP or older. For those goals, go with 4. A 32-bit system still offers some backward support for 16-bit programs and games.
I wasn't familiar with the server grade details because I don't really focus on that. I'm hoping DDR5 will be available for regular users too. Last year I considered purchasing a Threadripper with a motherboard to enable quad-channel performance, but I eventually stopped because it was too much for a gaming PC or my workstation needs.