The memory type advertised by the seller is DD4 (comparison page: Optiplex 5040 versus HP Z240).According to the DELL, this Optiplex model uses DDR 3 memory. I contacted the seller to clarify the discrepancy before purchasing. The seller confirmed that it is DDR4, and I ordered DELL Optiplex 5040. No miracles, the PC has DDR3 memory... Returning. Misleading product information and poor sales support. One star.