First of all, you need to note that mining by farms is not cheap. If you want your farm works regularly and for a long time, you need to properly take care of the quality and capacity of the equipment for it.
As usual, typical mining-farm consists of several graphics cards of one model (on average - 4 units), powerful power supply, motherboard with multiple PCI-Express slots and the CPU.
First of all, you should pay attention to the choice of graphics cards. How to understand what exactly is right for you?
The capacity of graphics cards is calculated in the kilohashes/sec from 100 to 1000 units. If you want your farm work effectively, you need to focus on the overall capacity not less than 1 megahash. Also, you need to remember that the greater capacity of the farm, the longer it can works for you.
Unfortunately, quickly buy the necessary model of graphics card is unlikely to happen, as they often are not available. So, those who rush to buy everything you need for your farm should be content with less efficient and less powerful units. But it's better than nothing. As usual, a good graphics card will cost from $ 600-900.
Now it's time to buy the other equipment. First of all it is necessary to buy a power supply. Do not forget that the mining-farm will consume a lot of electricity - three graphics cards consume about 800 watts per hour. Also - the work of the motherboard, CPU and other components. Therefore, it is recommended to take the power supply is not less than 900 watts, and even better - to 1300-1500. Also pay special attention to the cables. Typically, one graphics card needs two cables.
Also, an important aspect - it's extra cooling for the farm. As already mentioned, the graphics cards heat up very quickly, so you need to equipped your farm with an effective cooling system. If you are using four graphics cards, the best is to install about 12 ventilators with the maximum number of revs per minute to 2,200. As usual, ventilators are mounted without any problems on the bolts. Among the desadvantages of such ventilators you can note such a loud work - about 40 dB. You can also use the CPU cooler for the additional cooling. You can buy in a relatively low cost (about $ 20-50) 130 W power cooler with rotation speed of 2000 rev / min, and it will be quiet enough - not higher than 26 dB.
If your farm is to noisy, it is recommended to install an additional sound insulation. If your farm is "open", make for it a frame of drywall with a foam inside. If your farm is "closed-type", you can use a special sound insulating cover and place it on the inner walls of the box. Do not forget that the farm must be well ventilated.
As for the motherboard, there is only one requirement - the presence of connectors for RSI-Express.
When choosing a processor, memory and winchester - you can choose any, as they do not affect at the overall capacity of the farm.
Next, you need to buy risers - the special "extender" that allows you to take graphics card beyond the motherboard for a 15-30 cm. It is necessary to ensure the equipment of overheating, because the graphics cards heat up very quickly.
After buying the risers, it is time to take care of the farm stands - it can be a conventional shelving.
Now, when the all required items are purchased, it's time to assemble the farm:
1) Put the motherboard in the way to get enough air around;
2) Place a CPU, memory, power supply, HDD, etc. as in a conventional computer;
3) Suspend the graphics cards above motherboard at a maximum distance using the cable ties.
After this, install the Windows, the necessary drivers from the graphics card manufacturer's website and load the latest program version of cgminer.
Now, when the farm is collected, the case remained for small - to download the software and start mining. Step by step instructions on how to mine litecoins, you can find in the article "Mining litecoin - simple about difficult".