2.1 The IBM POWER9 processor2.1.1 POWER9 processor overview2.1.2 POWER9 processor features2.1.3 POWER9 processor core2.1.4 Simultaneous multithreading2.1.5 Processor feature codes2.1.6 Memory access2.1.7 On-chip L3 cache innovation and Intelligent Cache2.1.8 Hardware transactional memory2.1.9 Coherent Accelerator Processor Interface 2.02.1.10 Power management and system performance2.1.11 Comparison of the POWER9, POWER8, and POWER7+ processors2.2 Memory subsystem2.2.1 Memory placement rules2.2.2 Memory bandwidth2.3 System bus2.4 Internal I/O subsystem2.4.1 Slot configuration2.4.2 System ports2.5 PCIe adapters2.5.1 PCI Express2.5.2 LAN adapters2.5.3 Graphics accelerator adapters2.5.4 SAS adapters2.5.5 Fibre Channel adapters2.5.6 InfiniBand host channel adapter2.5.7 Cryptographic coprocessor2.5.8 CAPI adapters2.5.9 USB adapters2.6 Internal storage2.6.1 Backplane (#EJ1F)2.6.2 NVMe support2.6.3 Backplane (#EJ1C)2.6.4 Split backplane option (#EJ1E)2.6.5 Backplane (#EJ1D)2.6.6 Expanded Function Backplane (#EJ1M)2.6.7 Backplane (#EJ1D and #EJ1M)2.6.8 RAID support2.6.9 Easy Tier2.6.10 External SAS port2.6.11 Media drawers2.6.12 External DVD drive2.6.13 RDX2.7 External IO subsystems2.7.1 PCIe Gen3 I/O expansion drawer2.7.2 PCIe Gen3 I/O expansion drawer optical cabling2.7.3 PCIe Gen3 I/O expansion drawer system power control network cabling2.8 External disk subsystems2.8.1 EXP24SX SAS Storage Enclosure and EXP12SX SAS Storage Enclosure2.8.2 IBM Storage2.9 Operating system support2.9.1 Linux operating system