Effective IT management is often a balancing act between competing priorities. When your team’s duties include maintaining the health and performance of database VMs running Microsoft SQL Server, administrators will often face the challenge of completing routine operations like VM migration while having to minimize application downtime. Tools like VMware vMotion can aid migration by allowing admins to live-migrate a running VM with zero downtime—but there may be a tradeoff. Encrypted VMware vMotion migrations protect data in transit, but the encryption and decryption work consumes CPU resources. The CPU usage grows as VM sizes and migration activity increase. When migrations run long, they can overlap with production workloads, stretch maintenance windows, and detract from overall performance and efficiency goals. 

VMware Cloud Foundation (VCF) 9.1 directly addresses this tradeoff by supporting by default Intel QuickAssist Technology (QAT) acceleration for vMotion. Intel QAT can route the cryptographic work of migration to a dedicated hardware accelerator in some Intel Xeon Scalable processors rather than relying on general-purpose CPU cycles.  

For teams planning a VCF upgrade or a server refresh, there’s a practical question worth investigating: Can offloading vMotion encryption to Intel QAT produce a measurable reduction in migration time? We went hands-on with a server cluster to find the answer. 

How PT tested Intel QAT vMotion performance 

We used encrypted vMotion to migrate six SQL Server VMs under load between two hosts in the same Intel Xeon 6 processor-powered VMware cluster. We completed the migration with Intel QAT both enabled and disabled. The host configurations were identical, with only the Intel QAT condition changing. We measured total elapsed time for the six VMs to reach the destination host, ran the scenario three times, and reported the median.  

What our testing found 

  • With Intel QAT enabled, the six-VM migration completed in 1 minute and 32 seconds.  

  • Without Intel QAT, the same migration took 2 minutes and 3 seconds. 

  • Offloading cryptographic work to the accelerator via Intel QAT reduced migration time by 31 seconds, or 25 percent. 

What this means for IT teams 

VM movement is foundational to virtualized data centers, and its cost can grow with larger memory footprints and higher migration volumes. Faster migrations let teams finish workload moves sooner, evacuate hosts more quickly for patching and maintenance, and rebalance clusters as demands shift.  

Our SQL Server VM migration test results show that hardware acceleration with Intel QAT can make routine VM migrations faster and less intrusive, potentially freeing up CPU resources sooner and recovering admin time for other critical projects. Because VCF 9.1 enables Intel QAT by default on supported Intel Xeon Scalable hardware, teams can capture these gains without added reconfiguration efforts. For organizations planning a VCF 9.1 infrastructure upgrade, Intel Xeon 6 is worth considering for seamless QAT integration.  

For more in-depth information about our Intel QAT vMotion performance tests, check out our detailed report below.