You won't be able to install ESXi 6.5 on such hardware :/
Based on VMware vSphere 6.5 Release Notes
Upgrades and Installations Disallowed for Unsupported CPUs
Comparing the processors supported by vSphere 6.0, vSphere 6.5 no longer supports the following processors:
- Intel Xeon 51xx series
- Intel Xeon 30xx series
- Intel core 2 duo 6xxx series
- Intel Xeon 32xx series
- Intel core 2 quad 6xxx series
- Intel Xeon 53xx series
- Intel Xeon 72xx/73xx series
During an installation or upgrade, the installer checks the compatibility of the host CPU with vSphere 6.5. If your host hardware is not compatible, a purple screen appears with an incompatibility information message, and the vSphere 6.5 installation process stops.
Thanks Martin. Yes I know about the HCL etc that just wondered if there was a way to by pass it for my Home Lab.
From the list put up by Martin
Intel Xeon 51xx series - Woodcrest
Intel Xeon 30xx series - Conroe
Intel core 2 duo 6xxx series - Conroe
Intel Xeon 32xx series - Kentsfield
Intel core 2 quad 6xxx series - Kentsfield
Intel Xeon 53xx series - Clovertown
Intel Xeon 72xx/73xx series - Tigerton
The commonality that I see these CPUs are all before the Nehalem microarchitecture. None of these CPUs would have a feature called Extended Page Table (EPT).
I haven't seen any VMware document that explicitly states EPT or Secondary Level Address Translation (SLAT) is required for ESXi 6.5. But if ESXi 6.5 dropped software-based shadow paging and requires EPT, there would be no way to get around it. On the Workstation Pro 14.x/Fusion 10.x side, EPT is already a required feature from Intel CPUs to run.
Without EPT, you can only run 32-bit guests in a nested virtualisation environment. For example, you can create a VM that is running ESXi 6.0 but you can only run 32-bit VMs inside that ESXi 6.0 VM. And without EPT, I can imagine that it will also be very slow.
You could try creating a VM and attempt to install ESXi 6.5 in it, but it may not get tricked at all considering the absence of EPT and earlier failure to install bare metal ESXi 6.5; and that you are running ESXi 6.0 and trying to install an ESXi 6.5 VM (not the other way around).