Intel Optane persistent memory is a memory technology that can deliver larger capacities compared to traditional DDR4 memory. Virtual machine density can be increased by increasing the memory capacity of VMware vSphere by operating in memory mode.
Past experiments have found performance challenges with memory mode in certain situations. Two steps have been taken to address these issues. First, VMware recommends that memory mode be used in a 1:4 configuration as described in KB 67645. Second, Intel has developed a new Balanced Profile BIOS configuration to improve the performance of memory mode.
We have found a significant improvement in performance when using the recommended 1:4 configuration with the new Balanced Profile BIOS option. A single, very large VM saw a 1.75x improvement in its performance of an Enterprise Java workload, as shown in the below chart.
More details can be found in the performance study.