White Paper Multi-Core Servers Windows Server 2008 Windows* Server 2008, Multi-Core Servers, and the Future of Enterprise Computing [Windows Server 2008] will be entering the market at a time of dramatic change driven by related technology advances. We believe that Windows Server 2008 will act as a pivot point around which customers will adopt a collection of next-generation technologies on both the hardware and software sides. -IDC, July 2007 1 The IT industry is on the cusp of a new data center paradigm, driven by the impending release of Microsoft Windows* Server 2008 and empowered by the availability of 64-bit, multi-core servers. Together, these technology advances offer the foundations of a truly dynamic data center, able to deliver unparalleled business agility from a highly compact, cost-effective and efficient IT infrastructure. This paper discusses the advantages of adopting 64-bit, multi-core Intel-based servers as a platform standard during enterprise migration to Windows Server 2008, and the implications of these platforms for enterprise infrastructure and applications, and for business software development. Learn more at www.intelalliance.com/microsoft
White Paper Windows* Server 2008, Multi-Core Servers, and the Future of Enterprise Computing Table of Contents Parallel Tracks: Windows Server 2008 and Multi-Core Servers... 2 Windows Server 2008 and Multi-Core: Building a More Dynamic Data Center... 3 Multi-Core Infrastructure and Enterprise Applications... 5 Multi-Core and Software Development... 6 Evolving the IT Stack... 8 Parallel Tracks: Windows* Server 2008 and Multi-Core Servers From virtualization support to centralized server management and consolidation-friendly licensing, Windows Server 2008 has been designed for data center efficiency. Microsoft touts its new virtualization tools, Web resources, and security enhancements as a means to save time, reduce costs, and provide a platform for a dynamic and optimized datacenter. 2 New tools such as Internet Information Server 7, Windows Server Manager, and Windows PowerShell are designed to give IT administrators more control over servers and streamline Web, configuration, and management tasks. Advanced security and reliability enhancements like Network Access Protection and the Read-Only Domain Controller will help to harden the operating system and better protect the server environment. Coincident with the development of Windows Server 2008, server architecture has been evolving to meet enterprise demands. Traditionally, pressure for more and faster computing has been met with higher processor frequencies. Data centers scaled up and out, first with higher clock speeds in higher-end platforms, then with clusters of low-cost servers. More recently, server manufacturers have come out with 64-bit processors to increase memory addressability and enhance the performance of data-demanding applications. But the demands continue to increase, and with many data centers bursting at the seams and burning through their budgets, the IT industry needs platforms that deliver even more computing power in a smaller budget, space and power footprint. Enter multi-core processors, the next phase in server evolution. 2
Windows* Server 2008, Multi-Core Servers, and the Future of Enterprise Computing White Paper Windows Server 2008 and Multi-Core: Building a More Dynamic Data Center Companies can no longer afford the escalating hardware, power, labor, and facilities costs of continually adding more servers to meet demands. Server architecture has been continually evolving to address this issue. Through innovations in silicon process and new multi-core microarchitecture, Intel has continued to consistently deliver double the computing power within the same power envelope every 12-18 months. These platform improvements provide a foundation for optimization of the IT infrastructure. Building on this foundation, Windows Server 2008 offers a number of virtualization and consolidation options to help IT overcome data center bloat. Consolidation and Business Continuity Through Virtualization According to a 2006 Forrester survey, 60% of respondents said they planned to increase their use of virtualization. 3 In fact, IDC describes the new virtualization hypervisor capability in Microsoft Windows Server 2008 as the killer application for x86 64-bit Windows server operating environments. Little wonder, as virtualization provides the foundation for a truly dynamic data center, with the ability to improve everything from under-utilization to peak load responsiveness, system availability and security. Windows Server Virtualization (previously code-named Viridian ) is expected to be available approximately 6 months after the general release of Windows Server 2008. This new micro-kernelized hypervisor will host enlightened (lower overhead) or paravirtualized guest operating systems and will allow data centers to virtualize multiple operating systems Windows, Linux* and others on a single server. Along with the hypervisor, simpler, more flexible licensing policies such as the unlimited virtualized guest allowance in the Windows Server 2008 Datacenter Edition will help aid IT organizations in containing costs and increasing flexibility through virtualization. Delivering Energy Efficient Performance ~9x Reductions in Power per Core 110 Watts/ Core Single-Core 3.6 GHz Figure 1. Delivering energy-efficient performance As IT organizations plan virtualization under Windows Server 2008, they should also be planning to upgrade to quad-core servers. As shown in Figure 2, on the next page, quad-core servers can deliver more predictable performance for virtualized applications. 4 Configuring with one application per core leaves headroom for peak loads, significantly increasing server utilization with low implementation risk. 12.5 Watts/ Core Quad-Core Xeon 5320 >3x Performance Improvement (SPECjbb2005*) Single-Core 3.6 GHz Data Source: Intel measured results as of February 27, 2006 Quad-Core Xeon 5320 Quad-core-based servers provide a new level of value for clients, delivering three to five times the performance of systems that were offered just 12 to 18 months ago. These new systems enable clients to significantly grow compute power by upgrading or replacing their current systems while maintaining the same hardware footprint or consolidating applications onto fewer, more powerful servers. -IDC, 2007
White Paper Windows* Server 2008, Multi-Core Servers, and the Future of Enterprise Computing Quad-core Intel-based servers, with their higher performance density, are a natural fit for Windows Server 2008 business continuity and consolidation efforts. Since 2006, Intel quadcore processors have been providing the best performance available for mainstream servers. Quad-core architecture is available in all Intel Xeon processor sequences for systems ranging from entry-level 1-socket to ultra-scalable 32 sockets. 5 Intel Virtualization Technology (Intel VT) provides hardware assistance to the virtual machine manager (VMM), allowing the OS more direct access to the hardware and reducing computeintensive software translation from the VMM. This enables added capabilities for virtualized environments including mixed 32- and 64-bit configurations and Linux running on top of Windows. By reducing the size and complexity of the VMM, and making it independent of its guest OSs, Intel VT also reduces the potential for software conflicts that might otherwise slow or halt operations. Intel VT comes standard on multi-core Intel Xeon processor-based servers. Another advantage of multi-core Intel Xeon processor-based platforms is quick migration of virtual machines. Because the newest 4-socket Intel Xeon processor-based servers (Quad-Core 7300 series and Dual-Core 7200 series ) use the same Intel Core microarchitecture as existing 1- and 2-socket Intel Xeon processorbased servers (Quad-Core Xeon 5300 and 3200, Dual-Core 5100 and 3000 series ), system managers can build one pool of virtualization-compatible quad-core and dual-core servers and conduct quick VM migration between them, offering enhanced flexibility for fail-over, load balancing and disaster recovery scenarios. A new feature called Intel VT FlexMigration will allow the addition of future Intel Xeon processors to that same resource pool. 6 Experience has shown that consolidating on multi-core servers can yield significant savings. In one recent example, a data-intensive analytics application moved from multiple single-core servers to a single dual-core resulted in: 87% reduction in footprint 66% less power consumed $6,000 annual IT cost savings 7 Multiply this kind of savings across thousands of servers throughout the enterprise, and the ROI can be enormous. 12 10 8 6 4 2 Figure 2. MP servers offer more consistent performance as workloads increase. Consolidation with Microsoft Windows Terminal Services The new and compelling presentation virtualization features in Windows Server 2008 Terminal Services enable customers to use remote applications and seamlessly integrate them on their users client desktop and mobile systems. This is ideal for environments where you need remote access and data protection is critical. Multi-core architecture and 64-bit memory support allows these centralized data servers to support more users per server via terminal services. Application Virtualization with SoftGrid Microsoft Softricity* technology provides customers with application virtualization solutions that will allow Windows customers to reduce the TCO of desktop deployments. Applications are installed and managed centrally and then delivered directly to the user s desktop in a contained, virtualized image that does not interfere with or require interaction with the operating system itself or other applications present on the desktop. In addition, the Softricity technology provides application streaming which should enable end-users to get access to the applications they need faster than ever before. Predictable Virtualization Average Workload Completion Time Time in Minutes Dual-Core Completion time starts to increase as you add more virtual machines Quad-Core Less variation in performance results as you add more virtual machines Number of Workloads 1 2 3 4 5 6 7 8 One Quad-Core Intel Xeon processor 5300 series-based server One Dual-Core Intel Xeon processor 5148-based server SoftGrid provides a virtual platform for application installation, allowing the applications to move easily across banks of servers, thus allowing IT to leverage and better utilize the dense computing capabilities of multi-core servers.
Windows* Server 2008, Multi-Core Servers, and the Future of Enterprise Computing White Paper Multi-Core Infrastructure and Enterprise Applications To date, the IT industry has been slow to upgrade to 64-bit computing infrastructure. IDC notes that: Aside from obvious natural fits such as database software, high-performance technical computing, and other applications requiring large in-memory footprint, the rest of the business application portfolio remains 32-bit. 8 But analysts predict that the availability of Windows Server Virtualization only on 64-bit versions of the operating system will drive adoption of 64-bit server technology. Consolidation of enterprise applications on multi-core 64-bit servers running Windows Server 2008 will benefit business applications in multiple ways. Application Performance Decades of commercial application design for multi-processor servers will yield immediate benefits from multi-core processors. SQL Server 2005, Microsoft IIS and the Windows file server are good examples. The benefits of quad-core processors for these applications are greater efficiency and performance, lower power consumption, and lower price for the available performance. Typically, even 32-bit business applications will also experience performance improvement when hosted on 64-bit platforms. For example, platforms based on Intel Xeon processors with Intel 64 Architecture deliver up to 50% better performance than previous 32-bit platforms, even for existing 32-bit applications. 9 Business benefits will multiply as the larger memory addressability and speed of 64-bit computing substantially boosts the performance of applications designed and optimized to run on 64-bit hardware. Microsoft SQL Server 2005 on multi-core Intel-based servers is an excellent example. Intel platform technologies and multi-core processors immediately boost performance of SQL Server 2005. Intel processor-based servers are the first platforms to break the $1/tpmC mark on the TPC-C benchmark. 10 As illustrated in Figure 2, for well-designed applications, the more cores, the better. For example, the Intel Xeon processor 7300 series demonstrates up to 2x greater scalable performance 11 2.5x greater virtualization performance, 12 and 3x more performance per watt 13 than the industry-leading Dual-Core Intel Xeon processor and in the same power envelope. How Intel Core Microarchitecture Accelerates Applications Featuring 4 instructions per clock (instead of 3 typically found in other mainstream processors), each execution core is 33% wider and therefore more efficient at computing today s applications. (Intel Wide Dynamic Execution) Large on-die cache stores more data and instructions closer to the CPU so your server spends less time looking for data in system memory and more time processing it. (Intel Advanced Smart Cache) Out-of-Order Execution improves the performance of each core by intelligently loading or pre-fetching data in anticipation of the system s actual needs. (Intel Smart Memory Access) Taking advantage of multi-core processors is simplified by using Intel Software Development Products within the Microsoft Visual Studio* environment. Intel has designed the VTune Performance Analyzer, threading tools, performance libraries, and compilers to ease development transitions such as the performance-boosting moves to 64-bit and multiple core architectures. Application Responsiveness and Availability In addition to overall performance enhancement, the move to Windows Server 2008 on Intel servers and a more dynamic data center model will improve application responsiveness. Microsoft Server Virtualization s advanced features such as sub-socket partitioning and greater granularity of CPU and memory provi- sioning, plus the ability to do automated and policy-based system management using Windows PowerShell, will enable administrators to more easily and dynamically re-configure and re-provision the virtualized environment to ensure peak application performance. And multi-core servers can deliver more consistent and predictable performance results as more workloads are added. This provides IT more flexibility to add virtual machines and maintain service level agreements with internal business units and customers. 14
White Paper Windows* Server 2008, Multi-Core Servers, and the Future of Enterprise Computing Multi-Core and Software Development When considering the real impact of multi-core on application development, one pundit defined it as everything and nothing. Indeed, while many compute- and data-intensive applications benefit from the ability to scale software problems using multiple processors and threads, parallel processing on multi-core also tends to expose code bottlenecks that are otherwise not apparent in single-processor environments. Amdahl s Law says that the speed-up to be gained through parallelizing a problem is a function of the number of nodes available to share the work, their speed, and the percentage of the calculations that can be performed in parallel vs. the percentage that must be performed serially. In practice, parallelization is even more complex, because not all code is equally important to optimize, because parallelization can happen at many levels (OS, clustering, the application code itself), because optimizing complex problems can take a lot of domain expertise, and because performance can also depend on many system factors compute resources, memory and/or network bandwidth, disk I/O, etc. One can argue the benefits of one platform architecture versus another, which recently led one leading software executive to joke that if the code is not fully optimized, all microprocessors wait equally fast. In general, server-based workloads benefit from the fact that they tend to serve many users simultaneously. This provides the opportunity to benefit from system-level concurrency, even if individual requests, operations, or transactions are essentially sequential. This is why we can achieve good and fairly consistent scaling on server workloads as we add more processor cores. Parallelizing specific operations and transactions is a bigger challenge. In many instances, optimizing the ~10% of the application code that does 90% of the work can take 90% of the development time. The payoff is that as platforms become more powerful, well-optimized code can experience near-linear performance improvement. Better Tools Aid Application Optimization Development tools can greatly simplify and speed the process of optimizing applications for multi-core platforms. Ideally, development tools should automatically perform optimizations that take advantage of multi-core architectures, and they should be integrated with your development environment. Compilers can provide a degree of automatic parallelization. The Microsoft compiler has a variety of functions that can enable inherent parallelism. The Intel C++ Compiler for Windows and Intel Visual Fortran Compiler for Windows also perform sophisticated dependence analysis to figure out whether a loop can be parallelized safely without any #pragma directives. Parallelization improves application performance on multi-processor systems by means of automatic threading of loops. This type of option detects loops capable of being executed safely in parallel and automatically generates multithreaded code. Automatic parallelization relieves the programmer from having to deal with the low-level details of iteration partitioning, data sharing, thread scheduling, and synchronizations. These compilers are integrated into the Microsoft Visual Studio 2005 development environment, which includes basic support for parallel compiling and debugging. The use of math libraries that are pre-optimized for the underlying multi-core platform can also speed development and enhance performance. Additional tools, such as the Intel Thread Profiler and Thread Checker can also help developers understand how to profile their applications. These tools offer hints that will enable the developer to better understand the intricacies of writing well-threaded code. (Visit developer.intel.com for more details and whitepapers.) Scaling the Current Generation of Server Applications Most good server software is designed for and has had serious investment in scaling with multiple processors. In general, the current generation of commercial server-based applications is well threaded and will scale well on multi-core systems. The heart of the Windows Server 2008 operating system, the OS scheduler, is likely one of the most highly optimized pieces of code in the industry. This helps to highlight the query performance of Microsoft SQL Server 2005, one of the most parallel engines in the industry.
Windows* Server 2008, Multi-Core Servers, and the Future of Enterprise Computing White Paper Multi-Core Optimized Microarchitecture In 2008, Intel will launch a next-generation microprocessor codenamed Nehalem and with it introduce the revolutionary Intel QuickPath architecture. The scalable, shared-memory architecture will consist of low-latency Intel QuickPath memory controllers integrated into the microprocessor, which are stitched together with the high-performance, Intel QuickPath interconnect. The Nehalem microarchitecture itself is optimized for scalable, multi-core operation. Systems built with this processor will take full advantage of the interconnect technology to greatly increase the bandwidth and reduce the latency from processor to memory, processor to processor, and processor to chipset. This will enable software vendors to utilize the increased capability in future, multi-core processor architectures and increase the scalability of code running on Intel volume and high-end servers. The Nehalem processor will support a scalable number of one to eight plus cores and up to sixteen plus threads with Intel s Simultaneous Multi-threading Technology (SMT) across its product lifetime. The processor will support an on-die, Intel Quickpath memory controller to increase the efficiency of local memory access. Using Intel QuickPath interconnects between the processors will enable the system to readily share cached and uncached memory data between processors. In their popular computer architecture textbook, authors Hennessy and Patternson 15 refer to these as scalable, shared memory or distributed, shared memory machines. Also referred to as non-uniform memory architecture (NUMA), the Intel system configuration functions with near the efficiency of a coherent architecture. Software tuned for NUMA architectures will have improved performance on these systems, though almost all software will run better on systems with the Nehalem microprocessor. The combination of new core processor architecture, Intel 45nm process technology and revolutionary new system architecture, will ensure that next-generation software utilizing multi-core scalability will function at its peak and existing software will also gain, thus delivering the continued performance increases that software developers expect from Intel Architecture. A significant portion of today s server-based code, however, consists of custom IT applications that were built for single-processor platforms, and these applications will need to be re-engineered for full performance. Another issue for application scaling will be the front-end of the server code base, functions such as SSL encryption engines, file and print server functions, and web applications. Finally, there is the question of middle-tier logic. While there is a fair amount of parallelism built into middleware engines, mid-tier application logic will need to be reviewed for bottlenecks. For example, there is a big difference between reading a structure once in a DO loop and performing an operation on it 100 times versus reading the structure 100 times and doing something on it each time. Migrating to Multi-Core Windows Server 2008 will provide the impetus for standardizing on 64-bit multi-core platforms, and applications can reap the benefits. When migrated applications to multi-core, we recommend the following approach: Scope the effort of parallelization, identifying where it will have the biggest performance impact. Where application re-engineering doesn t make sense, look at how virtualization and consolidation can be used to improve application responsiveness. Make it an organizational requirement to address threading, scaling and performance in all future projects. Focus on building these skills within your IT organization: promote education in parallel programming, hire people who are good at it, and reward those who do it well. Encourage higher education institutions in your area to include parallel programming in their computer science curriculum. For business software developers, remember that 64-bit and multicore performance will be the ante for future business software, so invest in optimization now. And re-examine your licensing policies to be competitive in a multi-core server environment.
Evolving the IT Stack Traditional enterprise computing models and server architectures have reached their limits. Physical laws guarantee that the next levels of enterprise agility will not be achieved simply by cramming more transistors onto a silicon die or more servers into a data center. For more than 20 years, Intel and Microsoft have worked together to boost enterprise performance, lower data center costs, and reduce business risk. The capabilities of Windows Server 2008 on multi-core Intel-based platforms represent the next stage in IT evolution, the ability to consolidate business applications on a high-performance, flexible infrastructure that can adapt at the pace of business change. Upgrading to multi-core as companies migrate to Windows Server 2008 is the first step towards a dynamic data center and a more agile business. 1 Gillen, A. and Waldman, B. Windows Server 2008: A Pivot Point During a Period of Substantial Technology Change. IDC Report. July 2007. 2 http://www.microsoft.com/windowsserver2008/default.mspx. 3 Source: Server Virtualization Goes Mainstream, by Frank E. Gillett and Galen Schreck, Forrester Research, February 22, 2006. 4 Source: Intel IT, December 2006. Results compare one Quad-Core Intel Xeon 5300 Series processor-based server compared to eight Pentium III processor-based servers using a CPU-intensive database application modeling data analytics environment. http://www.intel.com/it/pdf/consolidate-using-quadcore.pdf 5 Note that Windows Server 2008 is currently limited to 64 logical processors and won t fully support 32 quad-core sockets. 6 This feature may not be supported in the initial release of Windows Server 2008. 7 Source: Intel IT, December 2006. Results compare one Quad-Core Intel Xeon 5300 Series processor-based server compared to eight Pentium III processor-based servers using a CPU-intensive database application modeling data analytics environment. http://www.intel.com/_it/pdf/consolidate-using-quadcore.pdf. 8 Gillen, A. and Waldman, B. Windows Server 2008: A Pivot Point During a Period of Substantial Technology Change. IDC Report. July 2007. 9 Actual performance will depend on specific applications and platform configurations. Intel has seen performance gains well above 50% for selected applications in internal tests. Typical gains have been in the 10 to 40% range. 10 Results as reported at http://www.tpc.org/tpcc/ as of February 17, 2007. 11 Performance measured using the SPECint*_rate_base2006 benchmark. Intel internal, early platform measurements (September 2007) comparing system configurations of four Quad-Core Intel Xeon Processor X7350 Series, 2.93 GHz, 2x4 MB L2 Cache, 1066 MHz system bus, with four Dual-Core Intel Xeon Processor 7140M, 3.40 GHz with 16M L3 Cache. 12 Performance measured using the vconsolidate benchmark result published on Virtual Iron 4.0 software. Intel internal, early platform measurements comparing system configurations of four Quad-Core Intel Xeon processor X7350 Series, 2.93 GHz, 8 MB L2 Cache, Clarksboro Chipset with four Dual-Core Intel Xeon processor 7140M, 3.40 GHz with 16M L3 Cache, 800 MHz system bus, Intel E8500 Chipset. 13 Performance measured using the SPECint*_rate_base2006 performance/watt benchmark. Intel internal, early platform measurements (September 2007) comparing system configurations of four Quad-Core Intel Xeon processor E7340 Series, 2.4 GHz, 2x4 MB L2 Cache, with four Dual-Core Intel Xeon processor 7140M, 3.40 GHz with 16M L3 Cache, 800 MHz system bus. 14 Source: Intel IT, December 2006. Results compare one Quad-Core Intel Xeon 5300 Series processor-based server compared to eight Pentium III processor-based servers using a CPU-intensive database application modeling data analytics environment. http://www.intel.com/it/pdf/consolidate-using-quadcore.pdf. 15 Hennessy, J. and Patternson, D. Computer Architecture: A Quantitative Approach. Morgan Kaufmann Publishers, 1990. Δ Intel processor numbers are not a measure of performance. Processor numbers differentiate features within each processor family, not across different processor families. 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