66 IBM eX5 Implementation Guide3.4 System architectureThis section explains the system board architecture and the use of the QPI wrap card.3.4.1 System boardFigure 3-7 shows the system board layout of a single-node 4-way system.Figure 3-7 Block diagram for single-node x3850 X5In Figure 3-7, the dotted lines indicate where the QPI Wrap Cards are installed in a4-processor configuration. These wrap cards complete the full QPI mesh to allow all fourprocessors to connect to each other. The QPI Wrap Cards are not needed in 2-processorconfigurations and are removed when a MAX5 is connected.Figure 3-12 on page 70 is a block diagram of the x3850 X5 connected to a MAX5.3.4.2 QPI Wrap CardIn the x3850 X5, QPI links are used for interprocessor communication, both in a single-nodesystem and in a 2-node system. They are also used to connect the system to a MAX5memory expansion drawer. In a single-node x3850 X5, the QPI links connect in a full meshbetween all CPUs. To complete this mesh, the QPI Wrap Card is used.SMIlinksMB 2MB 1MB 2MB 1MB 2MB 1MB 2MB 1Memory card 5Memory card 6Memory card 1Memory card 2QPIlinksIntelXeonCPU 3IntelXeonCPU 1MB 2MB 1MB 2MB 1MB 2MB 1MB 2MB 1Memory card 7Memory card 8Memory card 3Memory card 4QPIportsIntelXeonCPU 4IntelXeonCPU 2IntelI/O HubQPIlinksSlot 1: x16 FLSlot 2: x4 FL*Slot 3: x8 FLSlot 4: x8 FLSlot 5: x8 HLSlot 6: x8 HLSlot 7: x8 HL†IntelI/O Hub† Slot 7 keyed for the10Gb Ethernet adapterIntelSouthbridgeDual GbEthernetx4DVD, USB,IMM, LPSASx8* x8 mechanicalQPI QPIQPI QPIQPIports
