Barebone System Buying Guide What is a Barebone System? The barebone system is a brand new methodology in the building of the personal computer (server barebones are not covered in this guide) – it provides a pre-assembled combination of several basic components that a computer system must have, and leaves the ideal amount of room for the selection of important components that may be upgraded more frequently. With a barebone, the fun of DIY is kept intact, but the assembly process is made easier. Inside the Barebone As mentioned above, the barebone system consists of several basic hardware components that a computer must feature. They include: 1. The chassis, which is the shell and skeleton of the computer system. The chassis provides space and the necessary retention brackets and equipment on the inside for the installation of hardware components. 2. The motherboard, which can be considered the backbone of the computer. All other hardware components or devices must be connected to the motherboard to function properly. The motherboard determines the CPUs and add-on devices the system can support and is therefore a crucial choice when selecting a barebone system. 3. The third component is the power supply, which provides power to the computer system and its components. Most components and devices installed in a computer system receive power directly from the power supply. The majority of barebones consists of all three components, and may sometimes offer more, e.g. the CD/DVD ROM optical drive and/or the CPU cooler. All components inside a barebone system are preinstalled with all the necessary cables connected. The image below shows the internal architecture of a typical barebone. Inside a barebone DIY Capability The barebone is unable to run as-is as it is only a partially finished computer system. After you have purchased a barebone system, you need to complete it by choosing and then installing the other components it requires. The following table lists the key components that require a DIYer’s attention. Component Description CPU1 Also called processor, it interprets and executes instructions and data. The CPU roughly determines the performance of the computer and is an exciting choice to make. Memory Essentially the computer’s workspace – the place where the computer temporarily stores data and programs. Hard Drive A storage device, providing massive storage capacities for all types of data including images, documents, movies, music and games Video Card2 Responsible for delivering all of a computer’s hard work and resultant output to a connected display/monitor. Note: 1. A few barebones may pre-install or embed the CPU onto the motherboard. 2. Most barebones feature integrated onboard video. You may choose not to install a discrete video card if you are satisfied with the onboard solution. A barebone system installed with the key hardware components listed above is a functional one. Barebone users have the option of installing more components to enrich the functionality of the final product. Examples include adding an optical disc drive to read or burn CD/DVDs and a TV tuner card to receive TV programs. With a barebone system, it’s completely up to you! Barebone Styles Many users enjoy having their computers look as pleasant and appealing to the eye as possible. Featuring stylishly designed exteriors, barebones are offered in different shapes and sizes to meet a variety of requirements, be it expandability or the need to fit in with the rest of the living room. Barebones can be grouped under the following styles: Tower Barebones Looking much like the classic desktop computer, the tower barebone provides a relatively large amount of space inside for strong expandability and cooling. Booksize Barebones Booksize barebones impress for their slim proportions. They often feature compact internal architectures, which require the motherboard and the power supply to be of a certain design. Despite this, booksize barebones are compatible with most hardware components and devices. Mini Cube Barebones Featuring sound, well thought-out internal layouts, mini cube barebones can, despite being only half as tall as tower barebones (or even less), provide a satisfying amount of room on the inside for good expandability. This desirable characteristic has allowed the mini cube barebone to become more and more popular among the DIY crowd. The current trend is for smaller barebone systems that blend in well with other home electronic devices. Some barebones provide buttons and screens on the front end for operating system-free audio and video functions (this means that the user does not have to enter the computer operating system for basic CD or DVD playback). This type of functionality has helped to redefine the computer as the centerpiece of the total home entertainment solution. Barebone Specifications and Features Depending on the combination of the case, motherboard and power supply (as well as the other components and devices), there is practically no limit to the variety of barebone products available. Although it may seem like a challenge, finding the right product is not difficult at all – all it takes is an understanding of the specifications and features. Narrowing down should be quite easy afterwards. CPU Support Barebone motherboards usually provide one CPU installation socket. A very limited number of barebones support dual CPUs. In addition, the CPU socket roughly determines the type of CPUs that can be installed in the system. When it comes to the actual CPU frequencies and cores supported, look to the motherboard chipset as the key determining factor. This table shows the relationship between mainstream desktop CPUs and sockets. For example, if you wish to install a Pentium D CPU, please select a barebone system featuring a Socket LGA 775 motherboard. CPU Type CPU Socket Intel Pentium 4 Socket 478 or LGA 775 Intel Celeron Socket 478 or LGA 775 Intel Pentium D LGA 775 AMD Athlon 64 Socket 754 or Socket 939 AMD Athlon 64 FX Socket 939 AMD Sempron Socket 754 or Socket A The majority of barebones support desktop CPUs, but there are other barebones that are built to support mobile CPUs (e.g. Intel Pentium M). There are also a few barebones that come with the CPU already embedded (e.g. barebones featuring the VIA C3 CPU). This limits the expandability of the system, but also reduces the amount of research that needs to be done. If you require more information regarding CPU selection, please refer to our CPU Buying Guide and its related articles. The Motherboard Chipset The chipset is the core component of a motherboard, and the CPU support, graphics support (AGP or PCI Express), major I/O device support and expansion (add-in) card support all depend on the chipset. Since the motherboard is offered as a stock component in the barebone, when building a barebone, first choose the CPU, then find a barebone with a motherboard chipset that will support the CPU. The term “chipset” (sometimes called core logic) often refers to the two main chips on the motherboard: the Northbridge and the Southbridge (some vendors name their products differently, i.e. NVIDIA calls it either SPP or IGP or MCP, and Intel calls it (G)MCH/ICH). The Northbridge and Southbridge may also be combined into a single chip. This is called single-chip design. The Northbridge often refers to the chip that handles communications between the CPU, memory, AGP or PCI Express and the Southbridge. The Northbridge often includes the memory controller (the Northbridges supporting contemporary AMD CPUs are exceptions, as such CPUs integrate the memory controller). Some models will also contain an integrated graphics unit. The Southbridge provides connections to I/O devices, such as the PCI bus, USB, PATA, SATA and PCI Express devices. Other Southbridge functions include interrupt controller, real time clock, power management (ACPI and APM), SMBus and so on. Southbridge chips are usually connected to Northbridge chips. For more information on Intel and AMD platform chipsets, please refer to the following: Intel Compatible Desktop Chipset Guide AMD Compatible Desktop Chipset Guide Memory Support Barebones require the installation of memory modules to function properly. As a rule of thumb, more memory will allow more programs to be run simultaneously without system slowdown. Currently both DDR (Double Data Rate) and DDR 2 memory are used in barebone systems. DDR memory is widely used in Intel and AMD supporting barebones. Although DDR 200, DDR 266, DDR 333 and DDR 400 are all supported, DDR 400 is currently the mainstream choice. DDR 2 memory is very popular in barebones supporting Intel CPUs. There are currently DDR2 400, DDR2 533, DDR2 667 and even faster modules. Since AMD’s new AM2 platform will also support DDR2, we can expect new barebones supporting both AMD CPU and DDR 2 memory to appear shortly. Memory slots in barebones are often offered in pair(s), (e.g. 2 slots or 4 slots). This is because most barebones support dual channel memory mode, which can be enabled by installing one or two pairs of identical memory modules. In barebones that do not support dual channel mode, memory slots are provided purely for expansion of memory capacity. Please refer to the System Memory Buying Guide for more information regarding system memory. Hard Drive and CD/DVD Optical Drive Support Internal hard drives (HDD) are currently built using either the SATA or PATA interface, which are used to connect and transfer data between a hard drive (or CD/DVD drive) and the motherboard in a computer system. ATA is the acronym for Advanced Technology Attachment. It has been an industry standard hard drive interface for 15 years. ATA uses a 16-bit parallel connection to make the link between storage devices and motherboards, and is also called PATA to distinguish it from the newer SATA standard.