If you’re going to build a computer from scratch for a specific purpose, you’ll want to keep that purpose in mind when choosing your components; don’t just go to the store or an online shop and start buying. Consider what you want to use the computer for, you may be able to save money by specifying expensive, premium parts only where needed.

Any reasonably configured computer built from current components will offer adequate Internet browsing and word-processing capabilities. For an office computer, this is often all that is needed. As long as you provide enough RAM for your chosen operating system (256 MB to 1 GB for XP or Linux, 2 GB for Vista) any processor you can buy new will provide acceptable performance. If the computer is for gaming, a fast processor, the addition of a high-end graphics accelerator card (or two) and extra RAM will provide a more satisfactory gaming experience. Besides gaming, computers intended for video editing, serious audio work, CAD/CAM, or animation will benefit from beefier components which are specifically designed for that purpose.

Here are some general system categories. Your own needs will probably not fit neatly into one of these, but they are a good way to start thinking about what you are going to use your computer for. With each we’ve indicated the components you should emphasize when building the system and we’ve also included sample builds for each configuration , which you’re free to modify it to fit your needs and budget.

Simple Web Surfer

To provide basic functionality to a user who just needs web surfing, a little word processing, and the occasional game of solitaire, it’s important not to go overboard. Such a user has no need for a top of the line processor or 3D graphics card. A modestly configured system with an adequate Internet connection will suit this user best and can be assembled quite cheaply.

This usage pattern is not going to stress any particular component, you should be looking at a mid- to low-level processor (historically, and currently, at about the $125 price point or less), enough RAM for the OS and a mother board with built in Ethernet, video and audio. You can use a mid-level case/power supply combo (these components are often sold as a pair).

If you have a little extra money, spend it on a better monitor, mouse/keyboard, and case/power supply in that order.

Office Computer

An office computer can be expected to do word processing, spreadsheet and database work, network access, e-mail and a little light development of spreadsheets, databases, and presentations. It might also be called on to do page layout work, some 2D graphic creation, and/or terminal emulation.

None of this stresses any particular component either, but since office workers often run several applications at the same time, and because time is money in this space, a strong mid-level processor is suggested. Typically this would be the processor one or two places from the top of the line. Plenty of RAM will also facilitate multitasking and save time.

You will not need much in the way of 3D graphics power so current generation integrated graphics solutions from both AMD and Intel are perfectly adequate for office tasks. You should be aware that they will appropriate a portion of the system RAM for video duties thus reducing the total amount of RAM available for the OS and other programs so play accordingly and increase the total system RAM amount to compensate. Choosing the fastest operating frequency RAM your motherboard and budget can support will positively improve the performance of integrated graphics. If you decide that you need a dedicated graphics card after all, opt for an inexpensive model. A sub $75 (for this and other prices in US dollars see www.xe.com/ucc or other currency converter of your choice for conversion into your local currency) video card with 1 GB or more should be more than sufficient. However, do your research carefully because many inexpensive graphics cards actually have poorer performance than current generation integrated graphic solutions.

You’ll want a sturdy case (computers kept under desks get kicked by users and poked by cleaning staff) with a reliable power supply but nothing fancy. If you plan on keeping the system running nearly all the time, look for a power supply with a good reliability record. Any extra budget after the above should focus on a better monitor, better/more ergonomic mouse/keyboard and more RAM.

¹ – Nvidia Quadro(or AMD FirePro) models are generally intended for workstation models. While they cost quite more for the same graphics performance than their equivalent GeForce model , they are optimized for workstation programs and have a wider set of certified and approved drivers for these purposes. That said , most office users will be fine using a GeForce or Radeon(AMD) model.

²– For those who do not want to be bothered with overclocking , an i7-4790 could be a better choice and is slightly cheaper.

Server

A server these days can be anything from a home unit serving MP3’s and homework files to the kids, to a machine running a business-critical system for a small business, to a 3u rack mount unit serving up millions of hits a day on the Internet.

The thing that most servers have in common is that they are always on and therefore reliability is a key characteristic. Also they serve more than one user while storing and processing important information. For this reason servers are often equipped with redundant systems such as dual power supplies, RAID 5 arrays of four or more hard disks, special server grade processors that require error-correcting memory, multiple high-speed Ethernet connections, etc.

All of this is a little beyond the scope of the current work, but, in general, servers need lots of RAM, fast redundant hard drives, and the most reliable components your budget will allow. The CPU choice should be made in accordance with the use of the server. A simple print/fax server will do fine with a CPU stolen from a museum, whereas a server running a database and a front end for that, will work much better with a top of the line CPU.

On the other end of the hardware list, since nobody is usually sitting at them, you can get away with the cheapest possible keyboard, mouse and monitor (in fact many servers run “headless” with no monitor at all). Graphics are also a very low priority on these machines, and a read only CD/DVD-ROM optical drive (used, infrequently, for installing software and updates) will do just fine. We’re not including sample builds for this configuration because of the huge variety of possibilities.

Gaming System

We’re not talking here about the occasional game of solitaire or a secret late night Zuma obsession. We’re talking about cutting edge 3D gaming – first-person shooters or real-time strategy games with thousands of troops on the screen at the same time, with anisotropic filtering and anti-aliasing and mip-mapped specular reflections and a lot of other confusing terminology describing visual effects that will make anything less than a top-of-the-line system fall down on its knees and beg for mercy.

A top of the range processor is not critical to gaming performance (though it does help), but you will need at least a mid range one and plenty of RAM, as well as a motherboard to match, since the speed of the motherboard buses can limit high-end components. Please remember that if you plan on running the latest games in 1080p, or even higher, on highest settings, or even with three monitors, you will need a high end processor. This will stop the chances of bottlenecking the GPU (Graphic Processing Unit) and not give you the gaming experience you need. The most important part will be the video card (or cards) with cutting edge GPUs. ATI (who have been bought by AMD so the ATI cards now are labelled as AMD) and NVIDIA have been competing for “king of the graphics card” honors for years and the competition is so keen that new cards running on new GPUs are released, it seems, twice a month.

If you want to run two or more screens, the best idea would be to run two or more(up to 4) cards in either Crossfire X (AMD) or SLI (NVidia). But this is expensive and not all motherboards support both company’s methods, so do your research and buy the best current cards you can afford. Also be aware that not all types of Intel CPU’s can work fully with CrossFireX or Nvidia. For instance , all consumer Inter i7’s can utilize up to 16 PCI Gen3 lanes , with another 8 PCI Gen2 from the CPU(1/2 bandwith of x8 PCI Gen3). This essentially means that with these types of CPU’s , running more than 2 graphic card will be difficult as you may lose performance instead because there will not be enough bandwith for the graphic card(you’ll have to go for something like x4 , x4 and x8) , unless there is a PLX chip , which are not there in many motherboards. The Extreme i7 and the Xeons which do not use the same socket as the consumer products can utilize up to 40 PCI Gen3 lanes with an additional 8 PCI Gen2 lanes from the CPU. This is enough to fully power 4 graphics cards(at x8 , x8 , x8 and x16)

The other component which can offload some of the burden from your CPU is a good audio card. The DSPs (Digital Signal Processors) on the audio card can take over a lot of the sound processing and free up the CPU for other tasks. Currently Creative Labs and ASUS Xonar are the leading brands, but again do your research (partly by reading on) and get the best audio card you can afford. Some motherboards have audio cards already built in, though these are generally of lesser quality, depending on the quality of the motherboard.

Finally all of these components are going to require a pretty hefty power supply, particularly if you decide to run two graphics cards in Crossfire (ATI) or SLI (NVIDIA) mode, in which case make sure the power supply is rated for the dual-graphics card mode you choose. Generally a serious gaming rig will require at least a 500 watt supply; units are available up to 1500 watts (1.5 Kilowatts) and two Kilowatt supplies are more rare. Keep in mind that having a higher-rated power supply will not actually increase the power your computer draws. The rating is the maximum that the power supply is designed to provide. Get the best you can afford.

As you may have noticed, pretty much every component inside the computer needs to be top of the line; the same is true outside the case. You’ll want a big monitor, and a high sensitivity mouse. There are even gaming keyboards with the keys specially arranged, not to mention joysticks, throttle controllers, driving wheels, etc.

So, given that your budget is not bottomless, how do you prioritize? Well, the processor and video card are the components that will have the most effect on your gaming performance. Next comes the motherboard and RAM. If you use one instead of two or more video cards, you can also use a less expensive power supply. One of the advantages to building your own computer is that you can get the components you can afford now and plan to upgrade them later.

A note on cases for gaming rigs – it is not necessary to get a case with a side window that reveals glowing blue fans and revolving animated heat-sinks. A well-built plain case will do just as well and let you spend more money on the components that matter. But if you have the cash, and that’s your taste, there are lots of flashy add-ons available these days.

¹ – It means that 4 top-of the line Nvidia Titan X are used together in one PC. This therotically allows for up to a 400% boost in gaming performance compared to one graphics card , but there are limitations on the system , which brings it down to about 320%. Some games may also not work properly with SLI(AMD calls it CrossFire) , but most do. If you do use anything higher than Dual SLI , you cannot use the CPU shown on the ‘Performance’ build , rather you must go with something like i7-5930 K. You should also take power demands into account.

Entertainment System/Media Center

This is a computer designed to sit in the living room with the rest of your A/V gear. The idea is that it will record and serve audio and video files for replay via your existing television and stereo. The current notion is that this computer should be built in a special case that makes it look more like a stereo component, the size of which can present a challenge when it comes to getting all the necessary parts fitted.

For this system a mid-range processor will be fine, along with a generous amount of RAM. A fast Ethernet connection will facilitate sharing large files. You’ll also want a TV tuner card (or two) to get video in and out of the machine. Many of these also provide DVR(digital video recorder) functionality, often without the monthly subscription fees and DRM (digital rights management) restrictions required by companies like Tivo. A wireless keyboard and mouse provide for couch-based use and a separate monitor may be unnecessary as your TV will fill that role.

All components should be as quiet as possible since you’ll likely be watching/listening in the same room. For this application it makes sense to trade a little power for passively-cooled (without fans) parts. Following this logic, one may consider fan-less CPUs and mainboards.

Workstation

A workstation was, originally, a single-user computer with more muscle than a PC, intended to support a demanding technical application, like CAD or complicated array-based simulations of real world phenomena. The niche that these computers filled – between high end PC’s and low end minicomputers – has essentially evaporated. The serious scientific applications have migrated to clusters of PC’s with near super-computer speeds, and end-user applications, like video editing, music production and CAD, run well on high-end PC’s. One sector that still uses large workstation farms from Sun or Silicon Graphics is serious, Pixar-style animation.

For any of the following uses, you will need the fastest processor and the most RAM you can manage.

Video Editing

Big and fast hard drives are key. Solid State Drives or 10000 RPM Raptors in Raid 0 as working space with multiple 1 Terabyte or larger drives for storage is a good target. SATA/600 is highly recommended and SCSI subsystems should also be considered. A large amount of memory (8 gig or more, using a 32-bit OS is not recommended) would be beneficial, as would a fast CPU,with many cores/threads, especially if you intend to render effects or wish to quickly transcode video. Most editing and transcoding programs utilize some form of GPU acceleration (primarily OpenCL and/or CUDA), where the graphics processor is used, along with the CPU, to perform many calculations at the same time, greatly reducing processing time, compared to CPU-only processing.

Music Production

Plenty of disk space is important, you’ll also want at least 2 GB of RAM, but a music production (recording and mixing) workstation is chiefly distinguished by specialized external components – studio reference monitors instead of normal speakers, mixing consoles, microphones, etc. If you want to record external sources, like vocals or instruments, you’ll need an audio interface which allows you to plug mics or instruments into your computer.

Audio interfaces allow anything from a single microphone or instrument on up to pro level systems that have 32 or more simultaneous inputs. These separate inputs will allow you to record each one as a separate track in your DAW. Most use Steinberg’s ASIO interface (a software driver that connects your hardware to your DAW software). If you don’t wish to invest in anything other than the on-board sound card your computer comes with, consider ASIO4All, a free driver that imitates the ASIO framework for almost any sound card.

One piece of advice, if you have extra money, get better microphones – even if you have to trade the Bluesmobile.

CAD/CAM

(Computer Assisted Design / Computer Aided Manufacturing)

A CAD/CAM workstation is usually a machine that runs a single, very intense, application. These machines often utilize specialized video hardware, like the Nvidia Quadro series of GPU’s, which are designed specifically for CAD/CAM rendering. Since these machines are usually devoted to a single, expensive, application it’s especially important to pay close attention to the requirements of that application. Spec the hardware to support the software – always a good idea but especially important here.

Some examples of this specialized software are Autodesk 3ds Max, Autodesk Maya, AutoCAD, Cinema 4D and Maxwell Render among many others.

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