There are a number of Windows system metrics currently collected that turn out to be redundant and should be removed to save space:

• remove all "* Base" metrics, as these either measure sample time (in some units), or are some other metric that repeats information found in another metric.
  • except "\System\System Up Time Base" - it is required to compute uptime (with an unusual formula). Rather than include only this "Base" metric it would be ok if you prefer to do the special-case computation of uptime and simply emit a system uptime metric in place of both "\System\System Up Time" and "\System\System Up Time Base". (Actually this would be slightly preferable because the special-case uptime computation is a little inconvenient in downstream tools, but either way is fine.)

• remove the following as they duplicate another metric (albeit with a different "* Base" metric, but as above that "* Base" metric is already present elsewhere):
  • "\PhysicalDisk\Avg. Disk Bytes/Read"
  • "\PhysicalDisk\Avg. Disk Bytes/Write"
  • "\PhysicalDisk\Avg. Disk sec/Read"
  • "\PhysicalDisk\Avg. Disk sec/Write"