I am also thinking about making a render farm in the near future. Here are my thoughts and justification on the matter.
I have a budget, we all do. No matter how big or small it is, you dont want to spend in the wrong areas, when you could be getting performance rather than something that sounds impressive and really isnt going to be used all that much.
You will notice that there is a price to performance ratio with each cpu you buy. Benchmark different processors and find out what model of i7 (or amd or whatever you choose) is the most efficient.
You're not going to go out and buy a top of the line i7 that is 30% faster than another i7 that costs half the price. For this reason PLEASE do not buy top of the line. That's how marketing works... You want MORE render nodes not less nodes that run faster... that's the whole concept of scalability.
These days you can get a small, cheap i7 mainboard for around 95 dollars, and the core for 295. Dont skimp out on the power supply, so buy a good brand like corsair or thermaltake or one of the higher end gaming power supplies, but think about how many watts you really need! again dont rip yourself off. If you are smart enough with the specs you might be able to afford another one or even two extra nodes! and that will really translate into cpu power.
You want as many render threads on the screen at the same time as possible, that's your end game.
Oh another thing... My farm is entirely cpu based so I will be using cheap rubbish onboard graphics with shared video ram... I'll be cutting it down to 16 megs of shared video ram and probably going to be running them on very simple display modes. I will have no budget whatsoever on my (cpu based) render nodes. Sure on my main machine I'll have my old trusty geforce to handle all the display port stuff, but for the render nodes, they need minimal video card power! Dont waste money on this.
RAM. How fast? well the average i7 runs at 1600mhz so dont waste money on fancey sports ram with impressive cas latencies. just get normal el cheapo 1600mhz ram, I dont know you might want 16gb per node tops? you can always buy more later if you need it
hard disk on the nodes can be a 320 or 500gb seagate. I tend to avoid western digital and hitachi as they have faild me a few times in the past.
Dont waste much cash on storage, you can always buy a (seagate) nas later if you need it and use network based storage.
all mainboards come with onboard gigabit lan cards these days. make sure you also have a gigiabit switch. forget wireless.
you can get away with windows 7 or even xp home edition if you really want legit software
set up remote desktop software such as vnc or rdp so you can log into your render nodes for maintainence and check thier cpu levels.
if you need any help with this please contact me
https://www.facebook.com/annoni.moose
- Fabian