I use perfmon a lot :-)
So I'm always looking for new patterns.
Today I just happened to graph these two perfmon metrics against each other. Perfmon was collected with a 30 second interval here.
Its not too surprising that there is a difference. But how could there be *more* read IOs per second for the default workload group than the total on the server? (See just before 4:00 for a great example.)
Maybe if I sum the two metrics over the 4 hour period they'll even out?
23446639.19 << sum of LogicalDisk reads
22787670 << sum of default pool reads
Huh. LogicalDisk reads are 2.89% higher than default pool reads. Not too hard to believe - but for the small stretches where the default pool reads are significantly higher.
Works well for trending. Not so well if trying to accurately count individual reads.