Specifications

Chapter 4. Product information and technology 83
Intelligent threads
The POWER7 processor features intelligent threads, which can vary based on
the workload demand. The system automatically selects (or the system
administrator manually selects) whether a workload benefits from dedicating as
much capability as possible to a single thread of work, or if the workload benefits
more from having this capability spread across two or four threads of work. With
more threads, the POWER7 processor delivers more total capacity because
more tasks are accomplished in parallel. With fewer threads, workloads that
require fast, individual tasks get the performance they need for maximum benefit.
Memory access
The POWER7 processor chip in the compute nodes has one DDR3 memory
controller enabled (the second controller is not used, as shown in Figure 4-14),
with four memory channels. Each channel operates at 6.4 Gbps and can address
up to 32 GB of memory. Thus, the POWER7 processor used in these compute
nodes can address up to 128 GB of memory. Figure 4-14 gives a simple
overview of the POWER7 processor memory access structure.
Figure 4-14 Overview of POWER7 memory access structure
Advanced
Buffer ASIC
Chip
Memory
Controller
POWER7 processor chip
Integrated DDR3 memory controller
 High channel and DIMM utilization
 Advanced energy management
 RAS advances
Eight high-speed 6.4 GHz channels
 New low-power differential signalling
New DDR3 buffer chip architecture
 Larger capacity support (32 GB/core)
 Energy management support
 RAS enablement
DDR3 DRAMs
P7 Core P7 Core P7 Core P7 Core
P7 Core P7 Core P7 Core P7 Core