Each SQL Server environment has distinct system requirements and must be sized according to the instance-specific demands and the workload deployed. Workload characteristics in a SQL Server deployment include the nature of transactions, the expected user load, the required number of transactions per second (TPS), and the permissible levels of average query response time. SQL Server is a storage-intensive workload and requires high availability. The significant sizing considerations are server and storage.
For server sizing:
- Determine the type of processor that is best suited for handling the SQL Server workload requirements. The number of cores per processor and the frequency at which the processors operate are significant factors in selecting processors for any database solution.
- Determine the amount of required memory and allocate the DIMMs to the processor memory channels to take advantage of full memory bandwidth. Also, the amount of required memory for the database solution depends on database size, query traffic on the database, and average query response time requirements. The more memory that the SQL Server instance has the more data it can keep in its buffer pool and the less physical I/O it has to perform.
- Select the appropriate host network adapters based on the switches that are part of the solution. Networks can sometimes be a bottleneck in delivering results from the database server to the application client. For better compatibility and performance, select network adapters with a speed that matches the speed of the switches.
- Consider using two FC adapters for high availability and better performance, and ensure that the speed of the FC switches match the speed of the FC adapters.
For storage sizing and disk selection requirements, see Storage configuration.