By default, ESXi 5.5, 6.0, and 6.5 present SMBIOS 2.6 to VMs unless overridden. You can change this with advanced VMX settings:
For cloud architects, the guest SMBIOS version is not just a nostalgic detail. It affects licensing, templating, and OS activation. smbios version 26
Version 2.6 updated the Processor Information structure to better handle the rising core counts of the era. It introduced fields for and Core Enabled . By default, ESXi 5
Perhaps the most practical addition in version 2.6 was the full formalization of the structure. smbios version 26