The image shows the back panel of Oracle Database Appliance X3-2 with the two nodes on top and a storage shelf and storage expansion shelf under them. The image also includes an inset that shows the different socket configuration in the left-most PCIe card for Oracle Database Appliance models X3-2 and X4-2. Node 1 is at the top of the image. Node 0 is under Node 1. The storage shelf is under Node 0. The expansion storage shelf is under the storage shelf. . There are eight callouts. Callouts 1 through 4 are at the top of the image. Callouts 3 and 4 are at the bottom of the image. The table describing the function of each callout is located under the figures in this topic.