Dave Mishchenko has published a lot of tips and tricks about running ESXi and ESX 4.0 on unsupported, but working hardware. The list contains motherboards and unsupported servers that work with ESX 4.0 and / or ESXi 4.0 installable. Add your own known to be working model or take a peek at the list at http://www.vm-help.com.
This table contains a list of systems, motherboards, storage controllers and network cards that have been tested and found to work with ESX 4.0 or ESXi 4.0 Installable. Please check out the source column for a system you are considering using as some systems will include special steps to enable ESX / ESXi to run on that system or have other issues to overcome. None of these systems are supported by VMWare for running ESX.
