Designing successful Exchange 2013 solutions involves optimally sizing the hardware specifications of the Exchange servers. Hardware specifications include CPU, memory, storage, network, etc. These are very important components of the Exchange servers and under sizing any of them will give users a very poor experience.
In this article we will discuss how to determine the number of CPU cores required for a server, and also how to find the SPECint2006 Rate value of the CPU cores for given hardware. This determination is necessary to understand if the number of cores allocated is sufficient for the Exchange servers to take the load during normal operation and also in the case of one or more server failures.
One of the most commonly recommended and used server processors for Exchange is the Intel Xeon family. Figure 1 is a list of the latest processors available in the range. This table was taken from the following URL. Visit the Intel site via the link for the current range: http://ark.intel.com/products/family/78583/Intel-Xeon-Processor-E5-v3-Family#@All
Figure 1. Some of the latest release process
When designing Exchange Server solutions a useful tool to use is Exchange 2013 Server Role Requirements Calculator. At the time of writing this is at version 6.6. Visit : https://gallery.technet.microsoft.com/office/Exchange-2013-Server-Role-f8a61780 to get the latest release.
By default the Exchange 2013 Server Role Requirement Calculator is pre-populated with many design parameters, but the processor design settings are only partially complete. The the processor configuration, SPECint2006 Rate Value is set as zero. Figure 2 shows a screen shot from the tool. SPECint2006 Rate Value’s vary with the combination of processor model, core and server model. We need to determine the right processor model, core and SPECint2006 Rate value to give us the best user performance for the designed user count on each server.
Figure 2. Default Exchange Requirement Calculator SPECint2006 Rate Value
To calculate the value of SPECint2006 rate manually is a bit complex. To reduce complexity and errors, Microsoft provides the Excel based Processor Query Tool. This can be downloaded from: http://blogs.technet.com/b/exchange/archive/2012/04/30/released-processor-query-tool-v1-1.aspx
This tool helps to query the SPECint2006 Rate value for the given processor model. Based on the processor model input, it connects to the http://spec.org website, returning all test result data for the particular processor model.
As an example let’s take the first processor model E5-2699 v3 shown in Figure 1, and get the SPECint2006 Rate for the server model HP ProLiant DL 360 Gen9 (2.30 GHz, Intel Xeon E5-2699 v3). Figure 3 shows the results returned. It gives the SPECInt2006 Value as 702 for single (1) chip of 18 cores. You could also find the similar SPECInt2006 Value for other server models with varying chip and core combinations.
Figure 3. Processor Query tool result for processor model – Xeon E5-2699 v3
Once you have the SPECInt2006 Value for the server and processor combination in use, then update the process core and SPECInt2006 Rate value in the Exchange 2013 Server Role Requirements Calculator. Figure 4 shows the tool with the values inserted.
Figure 4. Update processor Core and SPECInt2006 Rate Value in the role requirement calculator
To determine if the processor cores are sufficient to handle the user load, click on Role required in the role requirement calculator and view the Role Requirements Results Pane – Server Configuration. Figure 5 shows a reference screen shot that Specifies the processor utilization (Server CPU Utilization) with the percentage when there is double server failure. It looks like this the process model with given cores and the server model would perform well and take up the users load on multiple server failure.
Figure 5. Process utilization details
You should try the tool with multiple processor types and different server model combinations to give you the best configuration result with the minimum number of processor cores. Since every environment has different user profiles and user counts, both of which play a role in determining processor and core requirements, it pays to try different scenarios in the Exchange 2013 Server Role Requirements Calculator. Other requirements also play a major role. For example, some organizations may require only two copies of the database while some may need more than two. With a change of the database copies, the server CPU core requirements will vary.
Virtualization also plays a role in the CPU requirement analysis. Smaller organizations with smaller user counts would normally go for full virtualization. In the virtualized environment, you would customize the number of cores allocated to each Exchange server and use their SPECint2006 Rate value.
I hope this article has thrown light on CPU designing for the Exchange 2013 environment. The Exchange 2013 Server Role Requirements Calculator is a great resource. It pays dividends to use it before deploying your Exchange servers.