This paper describes a simple but effective method to generate and observe the effects of external vibration on the read and write bandwidth of a disk drive. Furthermore, it quantifies these effects as a first-order numerical approximation. This paper is not intended to rate disk drives relative to manufacturer, model, size, form factor, ...etc. Rather it is simply intended to answer the simple questions of "Is there a performance impact of external vibration on a disk drive?" and "How significant is that impact?" After testing several 3.5- and 2.5-inch consumer-grade and enterprise-class disk drives the conclusion is that the consumer-grade disk drives are more sensitive to external vibration. In the presence of an external vibration caused by adjacent disk drive seek operations the bandwidth performance of a consumer-grade disk drive "feeling" these vibrations will decrease about 10%-15% when reading data and about 25%-40% when writing data. The final qualitative result of this study is that disk drive packaging is likely the most significant factor in reducing the vibrational effects.