Atomic clocks are used in high-precision navigation and timing systems, but choosing the optimal clock type requires a trade-off between accuracy and cost. In this study, we compared the performance of cesium and rubidium clocks using n seven-day numerical simulation based on four major sources of frequency drift, including environmental noise and aging. The simulation results showed that cesium clocks maintained higher frequency stability and more consistent performance than rubidium clocks, especially over short timing periods. A sensitivity analysis also revealed that certain physical factors have a greater impact on clock accuracy, most notably nominal drift and aging. These results indicate that cesium clocks provide more accurate performance under the same environmental conditions, justifying their adoption in critical applications that require the lowest margin of frequency error, despite their higher cost. Accordingly, we recommend developing techniques to reduce the production cost of cesium clocks or improve the performance of rubidium clocks to bridge the gap between the two types.