The author, Ed Bernier, a Sales Engineer at InfluxData, discusses the impact of cardinality on data ingestion in his InfluxDB Enterprise cluster. He sets up four different clusters with varying numbers of cores and memory to test the performance of InfluxDB under different conditions. The testing involves generating data using a utility called inch, which simulates streaming data for benchmarking purposes. The author finds that vertical scaling has a linear impact on performance, while cardinality has a significant effect on ingestion rate. However, there is an initial performance hit when creating new series, but once all series are created, the ingestion rate levels off. The author also observes that memory needed increases predictably as cardinality increases 10x. The study aims to provide insights into capacity planning for InfluxDB Enterprise environments and will be followed by a second part where horizontal cluster scale out is tested.