8456ch_components.fm Draft Document for Review January 22, 2020 8:31 pm The Power 9 systems support two NVDIMMs per CPC/CEC in regular, but designated,  memory slots.  The size of a BPM is smaller than a standard 2,5 inch disk drive module and fits into one of  the free CPC/CEC disk drive bays. In dependence of the config a maximum of two BPM  modules will be installed per CPC. Figure 2-29 shows an example of such a BPM. As the logic resides on the NVDIMM and the BPMs are connected directly to them the  movement of the DRAM to Flash works independently of the power state of the CPC/CEC  itself and this is even true when the CPC/CEC is already turned off by power loss.  The capability of the NVDIMMs is combined with the data protection concept of mirroring the  write cache NVS to the alternative node. Chapter 3.2, “CPC failover and failback” on page 72 explains this in more detail.  Figure 2-29 Backup power module  There are NVDIMM configurations in the size of 2x16GB or 2x32GB modules. They are  always installed in pairs of the same size. If the 16GB NVDIMM modules are used, one BPM  is sufficient to provide power to both modules in one CPC. In the case of the 32GB NVDIMM  modules, each module needs it own BPM module which summarizes the number of BPM to  four, two for each CPC.  2.6.6 Power cord options 2.6.7 Enclosure power supplies 60  IBM DS8900F Architecture and Implementation The power cord must be ordered for specific input voltage to meet certain requirements. The  power cord connector requirements vary widely throughout the world. The power cord might  not include the suitable connector for the country in which the system is installed. In this case,  the connector must be replaced by an electrician after the system is delivered. For more  information, see the  IBM System Storage DS8900F Introduction and Planning Guide ,  GC27-9560.  The CPCs, I/O enclosures, management enclosure and HPFE Gen2 feature dual redundant  PSUs for each enclosure. The PSUs are supplied power from the iPDUs. Each PSU in an  enclosure is supplied from different power domains for redundancy. That implies that the  power comes from different iPDUs, one on the left and one on right side of the rack. The 