The vLockstep technology used by FT requires the physical processor extensions added to the latest processors from Intel and AMD. In order to run FT, a host must have an FT-capable processor, and both hosts running an FT VM pair must be in the same processor family. The following table shows which CPUs are compatible with FT and can be used toegther in an FT VM pair. If an FT cluster mixes multiple processor types, they must be able to work together as shown by a green circle O where those the two processor types intersect in the table.
| Intel 3100 | Intel 3300 | Intel 5200 | Intel 5400 | Intel 5500 | Intel 7400 | AMD 1300 | AMD 2300 | AMD 8300 | |
| Intel 3100 | O | O | O | O | X | O | X | X | X |
| Intel 3300 | O | O | O | O | X | O | X | X | X |
| Intel 5200 | O | O | O | O | X | O | X | X | X |
| Intel 5400 | O | O | O | O | X | O | X | X | X |
| Intel 5500 | X | X | X | X | O | X | X | X | X |
| Intel 7400 | O | O | O | O | X | O | X | X | X |
| AMD 1300 | X | X | X | X | X | X | O | O | O |
| AMD 2300 | X | X | X | X | X | X | O | O | O |
| AMD 8300 | X | X | X | X | X | X | O | O | O |
CPU Speeds and FT : When ESX hosts are used together in an FT cluster, their processor speeds must be matched fairly closely to ensure that the hosts can stay in sync. VMware SiteSurvey will flag any CPU speeds that are different by more than 400 MHz.
You can read an overview of the VMware Fault Tolerance feature here.
