I was under the impression it had four slots, but opening the little panel on the bottom, and I only see two slots. However, when I look in CPU-Z, I see 4 slots. Maybe that's just because the program is designed to always have 4 in the dropdown menu. So the two memory cards I have in there are occupying the only two slots on the underside, but according to CPU_Z they're occupying slots 1 and 3.