As per this answer, I've configured perfmon to show
- Memory / Pages Input/sec
- CPU / CPU Time (%)
- Physical Disk / Average Queue length
(Names might be slightly different on an English version of Windows). Now I see these average values:
- Memory: 74.613 (1.000)
- CPU: 16.642 (1.000)
- Disk: 0.160 (100.000)
How do I interpret these values? CPU is simple (16.6% usage).
But how about disk? Is that 16 requests every second? Or 0.16? Or 0.0016? That doesn't seem right; the LED is flashing madly.
And page faults: Is that 74 page loads/sec?
For the fun of it, I've added "Physical Disk / Bytes read/sec" and "Physical Disk / Bytes written/sec". Here I get 235478.228 and 30568.626 respectively with a factor of 0.0001. Does that translate to 235MB/s read (implausible with a desktop harddisk) or 235 Bytes/s? Again the LED on the case indicates it must be much more.
Thanks a lot for clearing this up.
[EDIT] One thing which I figured out: The "factor" is to scale the value to be able to display it in the graph. The values below the graph (current, average, min, max) are absolute (or unscaled).
[EDIT2] Sorry, I mixed up the factors for memory and queue length.
[EDIT3] I'm on Windows XP/SP3.
And for those people who have been looking for the "Explain" button: 1. Click on "Add" (new indicator). In the dialog, there is an "Explain" button which tells you something about the currently selected indicator.
And a message to MicroSoft: If you supply a list box to select one option out of a whole lot, make that widget a bit bigger, okay? Scrolling wastes valuable human CPU power.
There is a free tool called PAL (Performance Analysis of Logs) http://www.codeplex.com/PAL which is intended to help read and understand performance logs. The author is an engineer at Microsoft. The tool has thresholds for many of the values recorded by perfmon. It might help.
The "Pages Input / sec" counter indicates that your machine is pulling in 74.613 memory pages per second from the pagefile (the (100) indicates that the value is being scaled in the display by 100). You need to graph "Page Reads / sec" counter and see if it is following the "Pages Input / sec" counter closely.
If you are seeing excessive paging, add the "Page Faults / sec" counter from the "Process" object for each process instance listed (besides _Total) and move thru them looking for the process(es) that are paging excessively. Bear in mind that "Page Faults / sec" is showing both soft and hard page faults for each process combined into a single total.
That disk queue number means that .16 requests were waiting in queue for the disk to become available per second. That number should normally be lower than the number of physical spindles in a RAID array, or under 2 for a single drive. This would be in line with you having a reasonably fast disk but having some excessive paging occurring.
Your disk reads are in line with the amount of paging you're seeing. Get to the bottom of the paging and life will be good.
The "Explain" button in Perfmon is your friend. Take a look at him.
Evan is right, the explain button should help, but more importantly make sure you are using the right tool to get the answer you want. You haven't said what you are looking at perfmon for. If you are simply wondering why the disk is spinning use process monitor under XP or the disk section of reliabilty and performance under vista/windows 7. If you are having a memory problem pages/sec would let you know as it's the sum of pages in and out to disk (remember that generally windows swaps FROM Disk not TO disk during a memory shortage and only pages out userdata- not applications)