Just some random thoughts on render farms while I sit here and wait for a rather long render to finish.

What's needed for a render farm...?  You just need loads of PCs.  But buying 10 or 20 PCs seems like such a waste, when all you really need are the processors, a tiny tiny hard drive, and a little memory.  You don't need optical drives or floppy drives (use USB ones, then you only need one drive!).

So here's my shopping list, for a 10 pc render farm:

1 x USB CD / DVD optical drive
1 x USB floppy (optional, you can even install windows by booting from CD)
10 x motherboards ( with USB and LAN )
10 x processors
10 x 256mb or 512mb memory
10 x tiny hard drives... whats the smallest you can get now, 40gb?  Even that is far too much space!
10 x Windows licenses

You'd need one monitor / keyboard / mouse set but if you've already got a desktop, use the ones from there (I just have laptops though hehe)...  But you only need these if all else fails... once you're all set up, then normally you'll be using remote-desktop or some such software to fiddle about on the nodes.

So the question is... where can you buy small PCs or even rack mount ones which only have motherboards processors, memory and say 10gb hard drives... or is this a job for eBay?

Let's have a discussion :)

Mark