Does the HP ProDesk 600 G6 SFF use full-size desktop DIMMs or laptop-style SO-DIMMs?

The HP ProDesk 600 G6 SFF uses full-size desktop DIMMs, not SO-DIMMs. This means you can use standard 288-pin DDR4 memory, which is often cheaper and more widely available than laptop-style sticks, making upgrades simpler and cheaper.