Intel's CI uses the "otc-gfxtest-" prefix for all hostnames (other than the master), and this is used to specify salt configurations. The "builder" role is separate from the other platforms, as it has no GPU and is used solely to build projects. Any fast server can fill the builder role.
For example, a sklgt4e system might support the labels "skl sklgt4e builder", because it can run a generic skl test project in addition to projects that run only on sklgt4e. It can also double as a builder, because it is a fast system for compilation.
If you just want to set up a basic test machine to execute the automation locally: