We have decided to deploy the Dell R815 platform and I was wanting to know if anyone has any suggestions on BIOS tuning parameters (recommended set of configurations) for ESXi 4.1.
The R815 servers are designed for virtualization and unless there is some specific reason to deviate from the defaults I would leave them. I would speak with Dell support if there is something in your environment that you need help with.
Check that Virtualization is enabled, and that you have the latest version of the BIOS.
Then other parameters usually work fine.
Andre