Hardware Reference
In-Depth Information
Mini-ITX motherboards are 170 mm (6.7”) square and are compatible with
microATX and full ATX cases and power supplies. Of course, there's usu-
ally little point to installing a tiny motherboard in a large case, so most
Mini-ITX systems are built in Mini-ITX cases, which accept only Mini-ITX
motherboards.
In the past, Mini-ITX systems were low-powered in every sense. They con-
sumed little electricity and used very low-performance processors. Most
Mini-ITX systems used passive cooling and “wall-wart” power supplies,
which eliminates fan noise and allows the system to be almost totally si-
lent. Mini-ITX was most appropriate for such “appliance” applications as
small Linux servers, routers, and satellite DVR playback-only systems.
That's all changed. Although you can still build an inexpensive, quiet, low-
power “appliance” Mini-ITX system—in fact, we'll do so as one of the proj-
ect systems in this topic—you can also build a high-performance Mini-ITX
system that matches all but the fastest desktop systems. Motherboards
like the GIGABYTE GA-H55N-USB3 and the Intel BOXDH57JG use the most
recent performance chipsets and accept mainstream and performance
processors like the Intel Core i3/i5/i7 models.
The main limitations of Mini-ITX systems all result from the small physical
size of Mini-ITX cases. For example, Mini-ITX motherboards may have only
one or two memory slots, rather than four or more, and only two SATA
connectors, versus four, six, or more on standard motherboards. Mini-ITX
motherboards simply aren't large enough to contain all the features and
connectors present on standard microATX or full ATX motherboards.
The small volume of Mini-ITX cases also puts strict limits on the size and
number of drives you can install. For example, some mini-ITX cases accept
only one 2.5” (notebook) hard drive and a slim optical drive. With some
Mini-ITX case/motherboard combinations, you're limited to integrated
video because there's no room (or slot) for a PCI Express video adapter.
The small volume of a Mini-ITX case also limits the size and number of
cooling fans. What fans are present must run at high speed to provide
sufficient cooling, so a typical high-performance Mini-ITX system will be
noticeably louder than an equivalent system built in a larger case. Finally,
Mini-ITX motherboards are usually more expensive, sometimes signifi-
cantly so, than comparable microATX or full ATX motherboards.
If you need to design a small PC, recognize that each step down from a standard
mini-tower involves additional compromises in performance, cost, reliability,
noise level, and other key criteria. Reducing case size limits the number and type
of components you can install and makes it more difficult to cool the system
effectively. It also makes it harder to quiet the PC. For example, small cases of-
ten use relatively loud power supplies. Because the power supply is proprietary,
installing an aftermarket quiet power supply is not an option. Similarly, using a
small case forces you to trade off performance against cooling against noise. For
example, you may be forced to use a slower processor than you'd like, because
the necessary CPU cooler for a faster processor is too large to fit in the available
space or is louder than acceptable.
