Does the Dell OptiPlex 3060 SFF support dual-channel RAM?

Yes, the Dell OptiPlex 3060 SFF supports dual-channel RAM with matched SO-DIMMs. Both slots are user-accessible, and installing matched DDR4 modules — 2 x 8GB is the sweet spot — enables dual-channel. It’s a straightforward, no-nonsense memory layout with no soldered or proprietary modules.