Hi ,
this is more Lightmass question rather than Swarm, cause Swarm only copies and deploys Lightmass tasks to remote machines.
Lightmass does its computation on CPU only. Its highly multithreaded, so the more cores the better. It is also recommended to have 1 Gb of RAM per thread (at least for big scenes). You’ll need to have WinXP or higher. There is also a strong recommendation for 64-bit system as it’s 30% faster and you won’t hit the out-of-memory exception if you install on that machine more than 4 Gb.
Sorry for the long response, but we have X-mass break :).
Jarek