• 8 x 2.5 inch SATA/SASThe images below illustrate the types of backplanes supported on PowerEdge R640:Figure 4. Back panel view of 2 x 2.5 inch hard drives with 1 PCIe expansion slotFigure 5. Back panel view of system with 3 PCIe expansion slotsFigure 6. Back panel view of system with 2 PCIe expansion slotsInternal chassis viewThe chassis design of the PowerEdge R640 is optimized for easy access to components and for efficient cooling. The PowerEdge R640supports up to 24 DIMMs, two processors, hot-plug redundant fans, system board and hard drive bays, and many other components andfeatures. For more system views, see the Dell EMC PowerEdge R640 Installation and Service Manual at Dell.com/Support/Manuals.Figure 7. Internal chassis view - 1 PCIe expansion riser12 Chassis views and features