The write cache allows transport database log IO to become effectively “free” and allows transport to handle a much higher level of throughput.Once we have our storage requirements figured out, we can move on to thinking about CPU. What a pleasant coincidence!
This means that in a worst-case failure event we would have 112 servers online with 2 failed servers in each DAG. If your hardware is larger than this, you should consider other options, such as using that hardware for other needs and buying smaller servers for your Exchange 2013 environment, or virtualizing.It is preferable to build more servers (scaling out) than it is to add resources to existing, larger servers (scaling up). Think of it as available space to grow into. For example, a segment of users might be considered “Information Workers” and spend a good part of their day in their mailbox sending and reading mail, while another segment of users might be more focused on other tasks and use email infrequently. We recommend using the SPECint_rate2006 benchmark from the The baseline system used to generate this guidance was a Hewlett-Packard DL380p Gen8 server containing Intel Xeon E5-2650 2 GHz processors. There are many factors to consider when sizing for required log capacity, and it is certainly worth spending some time in the Exchange 2010 TechNet guidance mentioned earlier to fully understand these factors before proceeding. As a result, the number of IOPS required to support transport is significantly lower. Transport also has storage requirements associated with the queue database. To understand why this configuration is recommended, please review in detail the posts The calculator does not take into account third-party products running on Exchange servers, or products that interact with Exchange (including internally developed applications), which means you must be sure to account for them during your sizing. The server garbage collector looks at the total number of There’s an important caveat to this recommendation for customers who are virtualizing Exchange. (16 databases x 65 mailboxes x 11.69 mcycles per active mailbox) + (32 databases x 65 mailboxes x 2.74 mcycles per passive mailbox) = 12157.6 + 5699.2 = Using the processor configuration mentioned in the megacycle normalization section (E5-2630 2.3 GHz processors on an HP DL380p Gen8), we know that we have 25,479 available mcycles on the server, so we would estimate a peak average CPU in worst-case failure of:That is below our guidance of 80% maximum CPU utilization (in a worst-case failure scenario), so we would not consider the servers to be CPU bound in the design. This is what we all have been waiting for :) Wow, such a BIG article, but I must say lots of things explained in details and I love the calculations ;)Very great article! This likely includes multiple database copies in one or more Database Availability Groups, which will have an impact on storage capacity and IOPS requirements. Since our computed memory requirement based on per-user guidance including memory for the CAS role (53.87GB) was higher than the minimum of 16GB, we don’t need to make any further adjustments to accommodate database cache needs.With the new architecture of Exchange, Unified Messaging is now installed and ready to be used on every Mailbox and CAS. It’s certainly acceptable to enable hyperthreading on physical hardware that is hosting Exchange virtual machines, but make sure that any capacity planning calculations for that hardware are based purely on physical CPUs. If virtualizing, hyper-threading may be enabled on the physical server, but each virtual server should only be allocated the required number of virtual CPUs (don't over-allocate virtual CPUs), and only utilize the physical processor core count for sizing calculations.In Exchange Server 2013 Service Pack 1 or later, you can enable SSL offloading to help reduce CPU consumption by Client Access servers, but the complex configuration of SSL offloading may not be worth the benefit.1 .NET Framework 4.6.1 requires post-release fixes if you want to install it on a server running Exchange 2013 CU13. it may be cheaper to configure 128GB of RAM compared to a smaller amount of RAM depending on slot options and memory module costs).Mailbox Memory per-server = (worst-case active database copies per-server x users per-database x memory per-active mailbox)For example, on a server with 48 database copies (16 active in worst-case failure), 65 users per-database, expecting the 200 profile, we would recommend:It’s important to note that the content indexing technology included with Exchange 2013 uses a relatively large amount of memory to allow both indexing and query processing to occur very quickly. We are talking about the Intel CPUs all this time, how about the AMD based servers? We recommend comparing the per-server memory requirement you have calculated with the following table to ensure you meet the minimum database cache requirements.
This helps to enable the ability to store multiple mailbox databases on the same JBOD drive spindle, and will also help to avoid bottlenecks on networked storage deployments such as iSCSI.