Performance Guidelines for AMD Athlon™ 64 and AMD Opteron™

40555 Rev. 3.00 June 2006

ccNUMA Multiprocessor Systems

 

bandwidth test, it exercises both of these modes of operation. The test serves as a latency sensitive test case when the test threads perform read-only operations and as a bandwidth sensitive test when the test threads carry out write-only operations. The discussion below explores the performance results of this test, with an emphasis on behavior exhibited when the test imposes high bandwidth demands on the low level resources of the system.

Additionally, the tests are run in undersubscribed, highly subscribed, and fully subscribed modes. In undersubscribed mode, there are significantly fewer threads than the number of processors. In highly subscribed mode, the number of threads approaches the number of processors. In the fully subscribed mode, the number of threads is equal to the number of processors. Testing these conditions provides an understanding of the impact of thread subscription on performance.

Based on the data and the analysis gathered from this synthetic test-bench, this application note presents recommendations to software developers who are working on applications, compiler tool chains, virtual machines and operating systems. Finally, the test results should also dispel some common myths concerning identical performance results obtained when comparing workloads that are symmetrical in all respects except for the thread and memory placement used.

1.1Related Documents

The following web links are referenced in the text and provide valuable resource and background information:

[1]http://www.hotchips.org/archives/hc14/3_Tue/28_AMD_Hammer_MP_HC_v8.pdf

[2]http://www.kernel.org/pub/linux/kernel/people/mbligh/presentations/OLS2004- numa_paper.pdf

[3]http://www.amd64.org/lists/discuss/msg03314.html

[4]http://www.pgroup.com/doc/pgiug.pdf

[5]http://www.novell.com/collateral/4621437/4621437.pdf

[6]http://opensolaris.org/os/community/performance/mpo_overview.pdf

[7]http://www.opensolaris.org/os/community/performance/numa/observability/

[8]http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/ multiple_processors.asp

[9]http://msdn.microsoft.com/library/default.asp?url=/library/en-us/memory/base/ virtualalloc.asp

[10]http://msdn2.microsoft.com/en-us/library/ms186255(SQL.90).aspx

[11]http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/ 529588d3-71bc-45ea-a84b-267914674709.mspx

10

Introduction

Chapter 1

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AMD 64 manual Related Documents
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64 specifications

AMD64 is a 64-bit architecture developed by Advanced Micro Devices (AMD) as an extension of the x86 architecture. Introduced in the early 2000s, it aimed to offer enhanced performance and capabilities to powering modern computing systems. One of the main features of AMD64 is its ability to address a significantly larger amount of memory compared to its 32-bit predecessors. While the old x86 architecture was limited to 4 GB of RAM, AMD64 can theoretically support up to 16 exabytes of memory, making it ideal for applications requiring large datasets, such as scientific computing and complex simulations.

Another key characteristic of AMD64 is its support for backward compatibility. This means that it can run existing 32-bit applications seamlessly, allowing users to upgrade their hardware without losing access to their existing software libraries. This backward compatibility is achieved through a mode known as Compatibility Mode, enabling users to benefit from both newer 64-bit applications and older 32-bit applications.

AMD64 also incorporates several advanced technologies to optimize performance. One such technology is the support for multiple cores and simultaneous multithreading (SMT). This allows processors to handle multiple threads concurrently, improving overall performance, especially in multi-tasking and multi-threaded applications. With the rise of multi-core processors, AMD64 has gained traction in both consumer and enterprise markets, providing users with an efficient computing experience.

Additionally, AMD64 supports advanced vector extensions (AVX), which enhance the capability of processors to perform single instruction, multiple data (SIMD) operations. This is particularly beneficial for tasks such as video encoding, scientific simulations, and cryptography, allowing these processes to be executed much faster, thereby increasing overall throughput.

Security features are also integrated within AMD64 architecture. Technologies like AMD Secure Execution and Secure Memory Encryption help protect sensitive data and provide an enhanced security environment for virtualized systems.

In summary, AMD64 is a powerful and versatile architecture that extends the capabilities of x86, offering enhanced memory addressing, backward compatibility, multi-core processing, vector extensions, and robust security features. These innovations have positioned AMD as a strong competitor in the computing landscape, catering to the demands of modern users and applications. The continuous evolution of AMD64 technology demonstrates AMD's commitment to pushing the boundaries of computing performance and efficiency.
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