OLTP 32 K and RDBMS 22 K use benchmark tests that reflect real-world workloads. This benchmark test can provide a reasonable expectation of performance in day-to-day production. Throughput benchmark tests do not reflect real-world workloads. Instead, throughput benchmarks are used to show the absolute maximum read or write performance that a particular configuration can achieve. In turn, the data from this benchmark can be used to help find the root cause of a resource bottleneck.

The chart below shows that in terms of performance, the 100 GbE configuration is delivering significant additional throughput over the 25 GbE configuration. In most cases, 100 GbE can achieve more than double the throughput achieved:

• Random writes: 106.2 percent increase
• Random reads: 138.6 percent increase
• Sequential writes: 92.3 percent increase
• Sequential reads: 126.4 percent increase

Note: CLM-007413; CLM-007414; CLM-007415; CLM-007416 Disclaimer: Based on internal Dell Technologies testing of a P670N 6 node cluster running VxRail 8.0.000 with vSAN ESA with 25 GbE and 100 GbE networking. February 2022. Actual results will vary.

Figure 4.   Results from 512KB throughput testing

As a storage workload, reads are typically not CPU bound but limited by the disk they are being read from. Also, when there is a hyperconverged infrastructure, the network those reads must travel over can limit read performance. In both test configurations, each cluster consists of six nodes, with each node running a pair of virtual machines that are generating the workload. As this workload is spread evenly across the cluster, the above throughput data can be divided by six (the number of nodes in the cluster) to obtain the throughput per node. As each node is configured with one active network port for vSAN, changes in cluster performance can be attributed to the hardware. In this case, that is the single network port on each node in the cluster.

Sequential reads on the 25 GbE cluster provided 3437 MB/s of throughput per node. This achieved throughput is slightly above the theoretical max throughput of 3200 MB/s that a 25 GbE port can deliver. The higher than max theoretical throughput can be attributed to one-sixth of the reads being served by the local node, while the other five-sixths of the reads traverse the network. For the 100 GbE cluster, the per node sequential reads throughput is 7792 MB/s, or 64 percent of the max theoretical throughput of 12800 MB/s that a 100 GbE port can deliver.