Not always hardware bottle necks are responsible for performance degradation. there are various possible reasons. And to detect the right culprit DBA should pay special attention to performance monitoring. For this purpose
- Regularly monitor your SQL Servers for blocked transactions.
- Regularly monitor system performance using System Monitor. Use System Monitor for both real-time analysis andfor historical/baseline analysis.
- If running SQL Server 2005, SP2 or later, install the free SQL ServerPerformance Dashboard. It can be usedfor real-time monitoring and performancetroubleshooting.
- Regularly monitor activity using Profiler.
- Be sure that traces are taken duringthe busiest times of the day so you get a more representative trace of what isgoing on in each server. When runningthe Profiler, do not collect more datathan you need to collect.
- Perform performance monitoring from a computer that is not the SQL Server you are monitoring. Run monitoring tools on a separate desktop or server.
Chosen from SQL Server DBA best practices By Brad M.mcGehee