How to build a Mini-ITX system

NOTE: This articles was updated on January 20th 2008. There might be newer models available than the ones mentioned in this article and we suggest you doublecheck everything before buying since we might have made an mistake. We don’t take any responsibilities for which products you choose to buy.

To make it easier for our customers to build a Mini-ITX system, this is short introduction what to shop.

Building a Mini-ITX system is not more complex than building any other computer. You need a case, motherboard, memory, harddrives and power supply. The difference is that there are not as many suppliers for the Mini-ITX market which makes it easier to choose.


We guess you visit our website to select one of our cases, such as the Mini File Server.


The biggest supplier for Mini-ITX motherboards is VIA. They have a catalogue for all their motherboards that gives you a good overview. One big difference, except for the size which is only 17 x 17 cm, compared to ordinary motherboards is that the VIA motherboards have the CPU integrated on the motherboard which means you don’t have to buy a separate CPU. There are other suppliers of motherboards like Jetway, however, these are not tested in our case.

To choose the right motherboard depends on your requirements such as:

Once you have answered these questions, you probably just have very few models to choose from depending on the price range you’re looking at.

One difference between all the models is also the CPU. In general, if you’re going to run the server as a headless server you will probably not need that much CPU power so the most cheap CPU available will probably be enough. We run Windows 2003 Server on the old EPIA 600MHz (M6000) without any problem but don’t expect good performance as a workstation.

However, we do recommend choosing one of the fanless models since CPU fans can be quite noisy. If you agree on that CPU selection is not the most important thing, it’s even easier! Below you will find the models available with SATA, and we will help you start ruling out models:

Then you can start ruling out some of the models depending on your need! When deciding between the models, use the catalogue to decide.

Most other models include differences in TV-OUT, COM-ports, firewire, number of USB-ports, number of memory slots and of course the price. Prices for the above models range from 115€ to 215€.



512 MB memory is usually enough for a headless server, but 1 GB is recommended depending if you’re going to run Windows, Linux etc. What kind of model or memory depends on what the motherboard support. Most motherboards have either 1 or 2 memory slots.



You probably already have harddrives that you want to put in the case. Make sure you have enough connectors to add them all. If you’re short on SATA connectors, you will probably need to to buy an extra PCI-controller. Also, we recommend that you choose the most silent drive you can find! The fan used in the Mini File Server is almost silent, so all you’ll hear if the harddrives spinning.


Power supply

To run it, you need a power supply. The difference from an ATX power supply is that Mini-ITX powersupplies have an external AC power adapter (also called brick), just like a laptop. Inside the computer case, you only have a small circuit board called DCDC-converter to where the power supply is connected via an extension to the back of the case where you connect the external power supply. From the DCDC-converter there is usually a standard ATX-cable connected to the motherboard and Molex/SATA-connectors. See below for pictures.

Power supplies range from 60W an up and the biggest difference is the size and price. Usually, the motherboard consumes up to 25W and each harddrive up to 10W depending on model. Mini-box offers an online power simulator to calculate your power needs. In our prototype we have a VIA EPIA EN12000EG running with 5 x 3.5″ SATA/PATA micture of harddrive and during idle it consumes 65W. There are even more details in our blog post regarding how much a Mini-ITX system consume.

Here are two example of suppliers and what they offer. Both models have been tested in the Mini File Server.

picoPSU. The following is included in their kit:


picoPSU picoPSU picoPSU

When you buy the picoPSU, by default, an AC power adapter (brick) is not included (#2 in the Morex product). Sometimes, stores offers bundles/kits so you get both the picoPSU and a power adapter. NOTE: Newer models of the picoPSU has 1 Molex and 1 SATA power connector.

Morex. The following is included in their kit:

Morex PDB080R Mini-ITX Power Supply

  1. Connect this cable to your wall outlet
  2. Connect the cable to this power supply. The PSU is stored outside the case.
  3. Connect the PSU to this outlet on the back of the computer case. The outlet on the back of the case is the black end of this cable
  4. The cable above is the connected to this DCDC-converter circuit board
  5. From the DCDC-converter this ATX cable is connected directly to the motherboard. This cable also has outlet for harddrives, floppies etc.


For best airflow, we recommend keeping cables to a minimum in the case.

There are shorter (from 10cm and up) SATA cables available.

Depending if you run harddrives with SATA or Molex power connectors you will probably need some power splitters to power all the harddrives. There are many configurations available, including a Molex -> 3 or even 4 SATA power connectors. However, most cable splitters are pretty long so make sure to get the shortest possible.


A highly effective and ultra-silent 120mm fan is included in our case.


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