We conducted the performance analysis and characterization testing (PAAC) on this solution using the Login VSI load-generation tool. Login VSI is an industry-standard tool for benchmarking VDI workloads. It uses a carefully designed, holistic methodology that monitors both hardware resource utilization parameters and end-user experience (EUE) during load testing.

We tested each user load against four runs: a pilot run to validate that the infrastructure was performing properly and valid data could be captured, and three subsequent runs to enable data correlation.

During testing, while the environment was under load, we logged in to a session and completed tasks that correspond to the user workload. While this test is subjective, it helps to provide a better understanding of the EUE in the desktop sessions, particularly under high load. It also helps to ensure reliable data gathering.

Login VSI installs a standard collection of desktop application software, including Microsoft Office and Adobe Acrobat Reader, on each VDI desktop testing instance. It then uses a configurable launcher system to connect a specified number of simulated users to available desktops within the environment. When the simulated user is connected, a login script configures the user environment and starts a defined workload. Each launcher system can launch connections to several VDI desktops (target machines). A centralized management console configures and manages the launchers and the Login VSI environment.

We used the following login and boot conditions:

• Users were logged in within a login timeframe of 1 hour, except during testing of low-density solutions such as GPU/graphic-based configurations, in which case users were logged in every 10 to 15 seconds.
• All desktops were started before users were logged in.

The following table describes the Login VSI workloads that we tested:

To ensure that the user experience was not compromised, we monitored the following important resources:

• Compute host servers —Solutions based on VMware vCenter for VMware vSphere gather key data (CPU, memory, disk, and network usage) from each of the compute hosts during each test run. This data is exported to .csv files for single hosts and then consolidated to show data from all hosts. While the report does not include specific performance metrics for the management host servers, these servers are monitored during testing to ensure that they are performing at an expected level with no bottlenecks.
• Hardware resources —Resource overutilization can cause poor EUE. We monitored the relevant resource utilization parameters and compared them to relatively conservative thresholds. The thresholds, as shown in the following table, were selected based on industry best practices and our experience to provide an optimal trade-off between good EUE and cost-per-user while also allowing sufficient burst capacity for seasonal or intermittent spikes in demand.

  Table 5. Parameter pass/fail thresholds for steady state utilization

  Parameter	Pass/fail threshold
  Physical host CPU utilization	85% 1
  Physical host memory utilization	85%
  Network throughput	85%
  Disk latency	20 milliseconds
  Login VSI failed sessions	2%
  Physical host CPU readiness	10%

• GPU resources —vSphere Client monitoring collects data about the GPU resource use from a script that is run on ESXi 6.7 and later hosts. The script runs for the duration of the test and contains NVIDIA System Management Interface commands. The commands query each GPU and log the GPU processor, temperature, and memory use data to a .csv file.

The following table summarizes the desktop VM configurations used for the Login VSI workloads that we tested:

*Task Worker testing was carried using an RDSH hosted desktop approach: each RDSH VM hosted a number of virtual desktop users and so the associated memory and CPU resources are shared between multiple users.