Quick Check Answer in Visual C#.NET

Encoder UPC-A in Visual C#.NET Quick Check Answer

If you want to maximize the number of onboard processors on your database server, you should opt for a 64-bit system. With Microsoft Windows Server 2003 Datacenter x64 Edition, you can run a total of 64 processors on one machine. For all other operating

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systems, however, the number of supported processes is the same in both 32-bit and 64-bit versions, as shown in Table 1-4.

Table 1-4

Operating System Windows Server 2003 Standard Edition Windows Server 2003 Enterprise Edition Windows Server 2003 Datacenter Edition

At the time of this writing, systems based on 64-bit processors are more expensive than those based on 32-bit processors. The costs of these systems and how they fit within budget limitations are, therefore, factors that you need to consider when designing your database server.

Despite the difference in cost between 64-bit and 32-bit systems, remember that hardware costs associated with selecting a processor tend to be minor in comparison with those of the SQL Server software itself. For example, a single, dual-core, 64-bit processor system would offer significant sav ings over a two-CPU machine based on 32-bit processors because the two-CPU machine would require double the licensing fees (assuming a per-processor license).

Driver support for 64-bit systems is more limited than that for 32-bit systems. If you buy a preconfigured server from a well-known vendor, built-in devices should be sup ported. However, if your server will use peripheral hardware, you should verify that the necessary 64-bit drivers are available.

When you are looking to support processing-intensive workloads, your fundamental choice is between scaling up and scaling out. Scaling up refers to increasing processing power within a single server, usually by adding multiple onboard processors. Scaling

out, in contrast, refers to the option of meeting high processing demand through a server farm. When you consider your business and technical requirements, if scaling up appears to be a more suitable solution than scaling out, a 64-bit system is a reason able CPU option because this platform offers potentially the most processing power within one server. If, on the other hand, your requirements are better met with a scaled-out solution, you no longer need to concentrate maximum power in a single server, and 32-bit servers in a network load balancing farm might prove to be more cost-effective.

Aside from the selection of 64-bit or 32-bit architecture (and aside from the obvious consideration about the chip speed), there are other features to consider when select ing a CPU. Some of these features include multicore architecture, hyperthreading, and L2 cache size.

A multicore CPU is one that includes two or more com plete execution cores. A multicore server running SQL Server can use each core as an independent processor and thereby increase multithreaded throughput. Hyperthreading, which is another feature that improves perfor mance, enables a CPU to execute multiple threads simultaneously. Conse quently, the CPU throughput increases. However, hyperthreading does not improve performance as much as a multicore CPU or multiple CPUs. L2 cache is memory that is external to the processor. Because increasing L2 cache can greatly improve performance, the amount of L2 cache associated with a given CPU should be a central consideration when selecting a CPU for your database server. However, a larger L2 cache does not improve the speed of activities that access data randomly.

To determine the number of processors needed to process the database application workload, simply choose as many processors as necessary to keep utilization below 75 percent (or whichever percentage you have chosen as your CPU utilization maxi mum). For example, suppose that you have calculated (by using the method described in the section Sizing a Database Server earlier in this chapter) that for your workload at peak capacity, the CPU utilization associated with a certain 32-bit 2.4 GHz processor is 250 percent. In this case, you can determine the number of pro cessors you need by dividing 250 by 75 (= 3.33) and then rounding up to the next