Chapter 6. IBM System x3850 X5 and x3950 X5 233Table 6-3 QPI port relationship to the processor socketFigure 6-9 shows the back of the x3850 X5 with the attached MAX5.Figure 6-9 Lab photo of an x3850 X5 (top) attached to a MAX5 (bottom)6.4.4 Accessing the DIMMs in the MAX5To add or subtract memory on the MAX5, you can remove the memory tray from the front ofthe chassis. Use the following steps to access the DIMMs:1. Remove ac power from all of the server’s power supplies and from the two MAX5 powersupplies. Because the QPI cables are already held in alignment by the memory expansionQPI port number Processor socket number1 42 33 24 1Important information about FPGA firmware: When attaching the MAX5 for the firsttime, reapply the FPGA firmware using the IMM firmware update tool after the server isplugged into ac power but prior to powering up the server.Do not use Bootable Media Creator or USXPI to update the FPGA until the FPGA firmwareis a match between the server and the MAX5. Mismatched FPGA makes the serverunstable and the server can power off during the flash, corrupting the FPGA. This situationresults in hardware replacement, because there is no recovery for corrupt FPGA.Important power considerations: With the server or MAX5 plugged into ac power andthe scaled units’ power turned off, the QPI cables still have active dc power runningthrough them. Only unplug or plug in the QPI cable when neither the MAX5 nor the serveris still plugged into ac power. Failure to follow this rule results in damaged circuits on eitherthe MAX5 memory board or the processor board of the server.
