A helpdesk technician is investigating performance complaints on a Windows workstation used for local database processing. While monitoring the system under load using Performance Monitor, the technician observes that the PhysicalDisk\Avg. Disk Queue Length counter consistently stays between 5.0 and 7.0. Meanwhile, CPU Utilization averages 18% and Available RAM is recorded at 62%. Which of the following is the most likely bottleneck causing the performance degradation?
- Storage subsystem throughputAnswer
- BPhysical RAM availability
- CCentral processing unit capacity
- DApplication architecture compatibility limits
Answer
Storage subsystem throughput is the primary bottleneck because the Average Disk Queue Length significantly exceeds the normal baseline threshold while CPU and RAM utilization remain low.
In Windows Performance Monitor, the PhysicalDisk\Avg. Disk Queue Length counter measures the average number of read and write requests queued for the selected disk drive. A sustained value greater than 2 per physical drive indicates that the storage drive cannot keep up with the volume of I/O requests, creating a system performance bottleneck. Because CPU utilization (18%) and Available Memory (62%) indicate plenty of available system capacity, the storage subsystem throughput is the sole bottleneck.
Step-by-Step Solution
Key Concept
Identifying storage bottlenecks using Performance Monitor disk queue length metrics