Hi, I found this to see my Hard disk bottleneck. In the System Monitor there are five Physical Disk counters for each physical disk contained in the Logical Drive that are key to identifying I/O bottleneck. Each disk should be investigated individually. 1. Avg. Disk Queue Length is the average number of both read and write requests that were queued for the selected disk during the sample interval. 2. Avg. Disk sec/Read is the average time, in seconds, of a read of data from the disk. 3. Avg. Disk sec/Write is the average time, in seconds, of a write of data to the disk. 4. Disk Reads/sec is the rate of read operations on the disk. 5. Disk Writes/sec is the rate of write operations on the disk. First, on the System Monitor properties window, slide the time interval to only include the period of â€œslow performance.â€ Then calculate the I/Os per disk as follows. Q1. System Monitor properties window, slide the time interval to only include the period of â€œslow performance.â€ Where is this ? I can't see anything under System Monitor-Properties? Q2. How long we should monitor and which value we should consider( average or maximum)? duration set 1:40?