POV-Ray : Documentation : Time Units in CPU Histogram
  POV-Ray 3.6 Documentation Online View System Specific Charset   3.1.6 Spelling Time Units in CPU Histogram

The CPU Utilization Histogram facility can output .CSV files containing system-dependent time units. For official compiles of POV-Ray for Windows, these units vary according to the results of the windows QueryPerformanceFrequency() API call. A scaling value is derived from this to prevent the values in the CSV file overflowing 32-bit integer precision (since the windows performance API returns 64-bit integers).

If you want to know what the actual value of the units in the CSV file is for your system, run POV-Ray for Windows with the /DEBUG command-line switch and observe the value that is printed in the message window when the program starts. On the author's system, this is 0.838096 microseconds. System Specific Charset   3.1.6 Spelling

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