IBM Power Systems 775 Manual

Contents

Chapter 1. Understanding the IBM Power Systems 775 Cluster 23Memory per drawerEach drawer features the following minimum and maximum memory ranges: Minimum:– 4 DIMMs per QCM x 8 QCM per drawer = 32 DIMMs per drawer– 32 DIMMs per drawer x 8 GB per DIMM = 256 GB per drawer Maximum:– 16 DIMMs per QCM x 8 QCM per drawer = 128 DIMMs per drawer– 128 DIMMs per drawer x 16 GB per DIMM = 2 TB per drawerMemory DIMMsMemory DIMMs include the following features: Two SuperNOVA chips each with a bus connected directly to the processor Two ports on the DIMM from each SuperNova Dual CFAM interfaces from the processor to each DIMM, wired to the primary SuperNOVAand dual chained to the secondary SuperNOVA on the DIMM Two VPD SEEPROMs on the DIMM interfaced to the primary SuperNOVA CFAM 80 DRAM sites - 2 x 10 (x8) DRAM ranks per SuperNova Port Water cooled jacketed design 50 watt max DIMM power Available in sizes: 8 GB, 16 GB, and 32 GB (RPQ)For best performance, it is recommended that all 16 DIMM slots are plugged in each node. AllDIMMs driven by a quad-chip module (QCM) must have the same size, speed, and voltagerating.1.4.9 Quad chip moduleThe previous sections provided a brief introduction to the low-level components of the Power775 system. We now look at the system on a modular level. This section discusses thequad-chip module or QCM, which contains four POWER7 chips that are connected in aceramic module.The standard Power 775 CEC drawer contains eight QCMs. Each QCM contains four, 8-corePOWER7 processor chips and supports 16 DDR3 SuperNova buffered memory DIMMs.Figure 1-12 on page 24 shows the POWER7 quad chip module which contains the followingcharacteristics: 4x POWER7 cores 32 cores (4 x 8 = 32) 948 GFLOPs / QCM 474 GOPS (Integer) / QCM Off-chip bandwidth: 336 Gbps (peak):– local + remote interconnect