How many default Cache Server instances are set when the number of cores is fewer than 8?

When the number of cores is fewer than 8, Tableau sets the default Cache Server instance to 1. The Cache Server is critical for optimizing performance by storing query results and other data, allowing for quicker access to frequently requested information.

With a lower number of cores, like when there are fewer than 8, the system does not have the capacity or need for multiple instances; having a single instance helps manage resources effectively without risking over-allocating them. Thus, for systems with fewer than 8 cores, one instance of the Cache Server strikes the right balance between performance and resource management.

In contrast, higher configurations might support more instances to utilize additional cores efficiently, but that doesn't apply when the core count is below the threshold of 8, which is why the designated number is set to 1 in such scenarios.