Lower Memory Costs for Virtualized SQL Server

Would you like to reduce memory costs of Microsoft SQL on VMware vSphere, while maintaining high OLTP performance? Read this solution brief to find out how!

E-commerce is built on online transactional processing (OLTP) and is essential to an increasingly digital-first world. OLTP applications require well-designed database solutions, such as Microsoft SQL, to store and process OLTP data. Performance of the database scales first and foremost with the amount of memory available and is critical to maintaining a consistent experience.
OLTP applications on Microsoft SQL are ideally suited for financial transactions, online retail and transportation bookings. OLTP use cases involve fast, effective querying across vast amounts of data where consumers expect real-time responsiveness. Businesses with e-commerce websites and data center IT management are seeking cost-effective solutions to address consumer expectations, comply with 24/7 SLAs, allow for scale and stay within budgets. Hosting SQL databases on VMware vSphere and vSAN is a great way to optimize resource utilization and consolidate licensing costs. Adding Intel Optane PMem can help reduce costs even more, while maintaining high performance

Benchmark tests reveal that deploying tiered memory with Intel® Optane™ persistent memory (PMem) supports the high-performance requirements of OLTP database servers while reducing memory costs by up to 49%. In other words, Intel Optane PMem can be used to increase memory capacity for a lower $/GB compared to an all-DRAM system. Intel Optane PMem provides nearly the same user experience as DRAM-only configurations in terms of new operations per minute (NOPM) and with negligible impact to power consumption.1 Tiered memory configurations are transparent to applications and require no software changes or modifications.

Using Intel® Optane™ PMem with Microsoft SQL databases deployed on VMware vSphere and vSAN provides the following: • Reduced memory costs. IT departments can use savings to spend on digital transformation and other innovations. • Improved cost efficiency. Increase memory capacity for a lower $/GB compared to DRAM. • Same impressive performance. Due to the technology of Intel Optane PMem, SQL performance is comparable to DRAM-only configurations at similar power consumption.

A typical virtualized Microsoft SQL Server 2019 deployment is based on SQL running inside VMs on VMware vSphere. The system uses Intel Optane technology for both tiered memory and vSAN storage, specifically Intel Optane PMem for tiered memory and Intel Optane SSDs as the vSAN write buffer.

As mentioned previously, DRAM acts as a memory cache and is not seen by SQL or the OS as part of system memory. As a rule of thumb, Intel recommends a DRAM-to-PMem ratio of 1:4. For example, a 2 TB OLTP system would use 512 GB of DRAM and 2,048 GB of Intel Optane PMem. An Intel Optane PMem module has the same form factor as a DRAM DIMM and plugs into the same physical DIMM connectors on the memory bus.

In summary, tiered memory with Intel Optane PMem reduces memory costs in virtualized SQL deployments and increases memory capacities, without sacrificing customer experience and impacting service-level agreements.