# Counters for System Performance

The following table shows the name, collection level, categories, and values for counters that measure system performance.

The VirtualCenter statistics level is a setting that controls reporting of metrics. Higher settings increase the amount of data collected and can impact performance.

- Level 1 collects resource use averages (but not for devices), uptime, heartbeat, and data for DRS (Distributed Resource Scheduler).
- Level 2 also includes usage summation and rollup types for the items above.
- Level 3 also collects device metrics in all the categories above.
- Level 4 also includes maximum and minimum rollup types.

Counter names in orange appear in the VI Client or other GUI.

### GROUP NAME: sys

Counter Name | VC Stats Level | Attribute | Value
--- | --- | --- | ---
uptime Uptime | 1 | description | Time elapsed since last system startup.
unit | seconds
stat type | absolute
rollup type | summation
entity | host and virtual machine
resourceCpuUsage Resource CPU Usage | avg: 3 min: 4 max: 4 | description | Resource CPU usage. CPU use by a resource such as console or helper application.
unit | MHz
stat type | rate
rollup type | average, minimum, maximum
entity | host and virtual machine
heartbeat Heartbeat | 1 | description | Number of heartbeats from the virtual machine during the performance interval.
unit | number
stat type | delta
rollup type | summation
entity | host and virtual machine