NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
initial performance results on ibm power6The POWER5+ processor has a faster memory bus than that of the previous generation POWER5 processor (533 MHz vs. 400 MHz), but the measured per-core memory bandwidth of the latter is better than that of the former (5.7 GB/s vs. 4.3 GB/s). The reason for this is that in the POWER5+, the two cores on the chip share the L2 cache, L3 cache and memory bus. The memory controller is also on the chip and is shared by the two cores. This serializes the path to memory. For consistently good performance on a wide range of applications, the performance of the processor, the memory subsystem, and the interconnects (both latency and bandwidth) should be balanced. Recognizing this, IBM has designed the Power6 processor so as to avoid the bottlenecks due to the L2 cache, memory controller and buffer chips of the POWER5+. Unlike the POWER5+, each core in the POWER6 has its own L2 cache (4 MB - double that of the Power5+), memory controller and buffer chips. Each core in the POWER6 runs at 4.7 GHz instead of 1.9 GHz in POWER5+. In this paper, we evaluate the performance of a dual-core Power6 based IBM p6-570 system, and we compare its performance with that of a dual-core Power5+ based IBM p575+ system. In this evaluation, we have used the High- Performance Computing Challenge (HPCC) benchmarks, NAS Parallel Benchmarks (NPB), and four real-world applications--three from computational fluid dynamics and one from climate modeling.
Document ID
20090024209
Document Type
Conference Paper
Authors
Saini, Subbash
(NASA Ames Research Center Moffett Field, CA, United States)
Talcott, Dale
(NASA Ames Research Center Moffett Field, CA, United States)
Jespersen, Dennis
(NASA Ames Research Center Moffett Field, CA, United States)
Djomehri, Jahed
(NASA Ames Research Center Moffett Field, CA, United States)
Jin, Haoqiang
(NASA Ames Research Center Moffett Field, CA, United States)
Mehrotra, Piysuh
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 24, 2013
Publication Date
May 19, 2008
Subject Category
Computer Operations and Hardware
Report/Patent Number
ARC-E-DAA-TN122
Meeting Information
14th Annual Meetin gof ScicomP, the IBM HPC Systems Scientific Computing User Group(Poughkeepsie, NY)
Funding Number(s)
WBS: WBS 106148.03.01
Distribution Limits
Public
Copyright
Other