Small form factor
From Wikipedia, the free encyclopedia
Small form factor (SFF) computers are used in reference to computers with an overall size that are smaller than the normal ATX motherboard based cases. While there is no clear definition of "small form factor" many believe it has to do with either the volume of the computer case or whether or not the case is limited to a microATX motherboard or smaller.
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[edit] Features
A typical SFF PC is similar to a shoebox or book size in dimensions with a fairly square front profile or small tower look. Expandability is very limited in some small form factor computers with most commercial offering only providing for one 3.5" and one or two 5.25" external drive bays. Standard heatsinks may not fit in a SFF computer, with some manufacturers opting for a bespoke cooling system, and generally these cases can only fit 2-4 hard drives. The recent boom of the "box type" cases has allowed for standard ATX PSUs to be used in SFF computers.
[edit] Types
There are many different types of small form factor computers available today. They can generally be divided into four types but keep in mind that there are others that use mini-itx motherboards and use other micro technologies.
- The first type is based on a barebones units (chassis, motherboard, power supply) in which the motherboard is laid out flat on the base of the computer case. The most common type of this SFF is the Shuttle Computer. Other types can be found from companies such as MSI and ASUS.
- The second type is sometimes referred to as a "box type" computer case. These SFF computers take mATX motherboards which, like the Shuttle Computer's products, lay flat on the base of the computer. These computers are normally not "barebone" systems like the Shuttle but have the ability to be upgraded easily. PC Design Lab's Qmicra, Aprevia X-Qpack, Ultra Micro Fly and Silverstone SG01 are all common types of "box type" SFF computers.
- The third type is mATX tower cases. These SFF computers look like a normal tower PC case but are much shorter and often come with a proprietary PSU. These cases, like the "box type", take only mATX motherboards. The Antec NSK3300 is a good example of one of these cases.
- The newest type is called ASFF which stands for "ATX Small Form Factor". This SFF type is for the larger small form factor computers that support full-sized ATX motherboards but are still contained in a smaller space. This version is being developed by BOXGODS.com and SFFClub.com.
[edit] Uses
As a result of the smaller motherboard, SFF computers can be far smaller than typical computer cases and are often used in space limited confined areas where normal computers cannot be placed. SFF computers are finding a niche as Home theater PCs(e.g. AOpen's miniPC) as well as for Mobile applications such as LAN parties. Small form factor PCs are also commonly used in industrial applications by Scientific, Military, Telecommunications, Industrial, and Control markets.
[edit] New Standard
On January 10, 2007 AMD announced a new standard for SFF motherboards called DTX. This is supposed to be the first true standard for small form factor computers and may redefine the industry. The standard is only for the motherboard but it calls for a standardized meaning of "SFF".
The dimensions of this motherboard are to be 200mmx244mm whereas mATX is 244mmx244mm.
According to AMD the following aspects were addressed with DTX:
- DTX, which will allow up to four motherboards – for low cost – per standard printed circuit board manufacturing panel sizes; and
- Mini-DTX, which will allow up to six motherboards – for low cost – per standard printed circuit board manufacturing panel sizes;
- DTX motherboards can be manufactured in as few as four-layers of printed circuit board wiring for motherboard cost savings.
- By leveraging backward-compatibility with ATX infrastructure, vendors may gain a low-cost DTX product offering with little development expense.
