3 RAM Speeds the HP ProDesk 600 G6 SFF Supports
2666 MHz Regarding the HP ProDesk: The system runs at this speed if you install DDR4-2666 modules.
2933 MHz It also supports DDR4-2933, offering a middle-ground performance boost.
3200 MHz For the fastest option, use DDR4-3200 modules. The motherboard automatically adjusts to whatever speed you install, up to 64 GB across two SO-DIMM slots with non-ECC unbuffered RAM.