|While a simple question, it does not have an easy answer. Systems can show up having 100% CPU utilization and function well. Others can show 100% utilization and perform poorly. Using utilization alone as a performance metric is essentially useless. Similarly, memory utilization is not a performance metric alone. A well running system should show 90%-95% memory utilization. Why have memory unused when there is paging going on. By the same token, perhaps the system only has a few processes performing work that only require small memory totals and there is 50% memory utilization. In this case, no paging is happening, so the system is performing well.|
The bottom line is that performance evaluation includes an in depth knowledge of the application environment as well as performance metrics in order to understand the data within the context of the environment.
There are performance tools available (both free and for a price) that can gather and display performance data in whatever timeframe you desire.
Perhaps a better question would be to focus on the performance problem or issue and request a method to resolve it?