So I'm not a network guy - but here's what I want to do - I have an existing network using wifi, which I like, and which is used to connect several computers to the internet. It is headed up by a router, which is in another part of the building.

Three of those computers are in my office. All three have gigabit wired ethernet. I have a gigabit switch. Here's what I want to do:

Build a 2nd network, out of just that switch, which allows all 3 computers to connect to each other (just to each other is fine, for this purpose, they need no internet).

I have a distributed computing task (rendering high-quality fractal artwork, as it were), that requires the best connection speed to all 3 computers. I want them to be able to "talk to each other" as quickly as possible, with the fewest dropped packets (the dataflow over this network will be quite high).

So how do I do this. I'm not a networking guy at all - I tried connecting them all, and nobody got an IP address (which I assume is because nobody is running a DNS server?).

What all do I need to do to make this work?

PS - two are running windows, one is running ubuntu.