Table of Contents
Overview
As a custom computer builder, we get a lot of people asking for help designing high-end computers. Many times they are for media editing, stock trading, or research – but one of the most common uses of such powerful systems is video games. Given how much interest there is in gaming computers, I wanted to provide a guide for how to select what components to use in a modern gaming computer. There are lots of review sites that talk about specific hardware recommendations, but those are outdated quickly – so this article will focus more on the ideas behind the various parts of a custom gaming computer and what you need to take into consideration when building or purchasing one.
The main components in a computer that affect gaming performance are the RAM, CPU and video card (not necessarily in that order) – balancing those three items, and making sure each are sufficient for the sorts of games you plan to play, is crucial.
RAM (Random Access Memory)
Memory speed is also something to consider, though much less important than having enough RAM. There are four factors that go into the “speed” of memory:
1) Memory type – DDR (double data rate), DDR2, DDR3, etc. Each new standard allows for higher bandwidth, discussed next, but usually at the cost of higher latency (the third factor). There are also other improvements made with each generation, though, which can contribute to better performance.
2) Bandwidth, measured in MB/s (PC2-6400, as an example, theoretically provides 6400MB/s) or MHz (PC2-6400 is also known as DDR2-800, for 800MHz). The more bandwidth there is the more total memory can be moved around per second, which can help with gaming – but since all memory today is high-speed in this regard it doesn’t make a massive difference.
3) Latency, measured in clock cycles. This will sometimes be broken out into several specs, like 4-4-4-8, or often just shortened to one – like CL4 (CAS Latency 4). Lower latency means that when a bit of data is requested it takes less time to find it, which translates to slightly faster overall performance.
4) Memory controller technology also has a big effect on performance, but it does not lie in the memory modules themselves. The memory controller is the circuitry that keeps track of where things are and moves memory around to the places that need it (in very basic terms). It adds to latency depending on how efficient it is, and can support things like multi-channel memory access. Dual and triple-channel memory configurations improve performance by effectively doubling or tripling the maximum bandwidth, but as alluded to in the section above once you hit a certain point additional bandwidth doesn’t help with gaming computers. As a side note this is why memory is best added in pairs or sets of three, depending on the number of channels being used.
A bigger factor to consider with memory controllers is their location. Traditionally memory controllers were a part of the chipset, so when the processor needed to access data it had to tell the chipset which in turn would find the correct spot in memory and then transmit it back to the CPU. To make that path more direct memory controllers are moving to the CPU itself on many newer platforms. AMD was the first to do that, and all of their processors from the past couple of years have incorporated such technology. With the Core i7 Intel adopted this approach as well – and further designs based off that chip should also have integrated memory controllers. Making a purchasing decision solely on the placement of the memory controller is probably not a good idea, but it is something to consider when looking at a gaming computer as a whole.
CPU (Central Processing Unit)
The term ‘CPU’ is often misunderstood – some people think it refers to a whole computer, or at least the “tower” portion, and others just don’t realize it is an acronym. It stands for Central Processing Unit, and is synonymous with the term ‘processor’ when discussing modern computers. Many like to think of it as the brain of a computer, and it is indeed the component responsible for most of the computations done in everyday applications. When it comes to gaming, though, it shares responsibility with the GPU, or Graphics Processing Unit, which is located on the video card. It is important to realize that there is a balance between these two types of processors: if you have far more CPU power then performance will be GPU-limited, and vica-versa.
Since the CPU is responsible for general types of computation, rather than graphics, its role in gaming is to take care of player input, AI, game mechanics, and sometimes physics. The more complex a game is in those areas the more processing power and speed you will want from the CPU – for example, in strategy games having multiple computer-controlled factions will put a strain on AI processing; a faster processor can help with that. Simulation games also tend to be more CPU-limited, since there are a lot of details going into making the simulation as accurate and realistic as possible.
There are a few different characteristics of CPUs to take into account when selecting one for your computer:
1) Brand – Intel and AMD are the traditional major CPU manufacturers, and each has different approaches to CPU design. Furthermore, they use different motherboards which will affect other component choices – so picking a platform on this level is an important choice.
2) Processor family or architecture – Within each brand there are usually two or more CPU types; the Core i7 and Core 2 from Intel are a good example. They use different sockets, and so different motherboards and CPU coolers, and each has its own advantages. If this article were to cover specifics like that it would not stay relevant very long, as new architectures are introduced relatively often – but there are plenty of online resources for getting details and comparisons of the latest options. Hardware review sites in particular are good places to check out, or other articles and blog posts here at Puget.
3) Number of processor cores – In the past, a CPU could only work on one thing at a time and had to constantly alternate back and forth between different active programs. As multitasking (running many applications at once) became popular and software in general needed more processing power this turned into a problem: CPUs could only be run so fast, and development was outrunning advances in pure processor speed. The solution was to begin processors with multiple cores, and we now find that there are dual, triple and quad-core options – with six and eight cores probably not far off. Getting at least a dual-core is easy, and for some uses it may be beneficial to go further. Games traditionally have not been designed with multiple core systems in mind, but that is changing – so look into reviews of the games you want to play, paying special attention to how they perform on different types of hardware, and purchase a processor accordingly.
4) Processor speed – Within a single processor brand and family you can compare clock speeds (often given in MHz or GHz, which are 1000MHz) and use them to help decide what processor offers the best value. Assuming that your game or application is entirely CPU limited, moving up 10% in clock speed (say from 3GHz to 3.3GHz) will result in roughly a 10% gain in performance. If you are not CPU limited, then you might see no difference at all – but all other things being equal a faster processor will at least never result in slower performance. A general rule of thumb is to go for the fastest processor that does not necessitate a massive jump in price, but depending on your exact needs that may be overkill or not enough. Again, there are great resources online to help you determine what exact model will best meet your needs.
In addition to these there are other properties of CPUs: cache, front-side-bus (or other equivalents), etc. Those are generally fixed for any processor family, or at least for subsets of that family, and while they can be useful in helping to decide what processor architecture to go with they are not generally worth looking at on their own. They can also be deceptive, as there are different aspects to many of the specifications of a processor which can make direct comparison across architectures problematic. Looking at actual benchmark performance results is the best way to determine what you need, or what will best fit your budget.
GPUs (Graphics Processing Units)
The third major consideration in building a custom gaming computer is the graphics system – consisting of one or more GPUs spread across one or more video cards. Traditionally there was one GPU on a video card, along with some supporting memory (making almost a small computer on its own) – but like everything else in computers that wasn’t enough and has gotten more complex. There are now video cards with two GPUs on them, and there are standards for using multiple video cards in tandem to further improve performance. This is almost akin to multi-core processors, in that some games can benefit from multiple GPUs and some cannot; in this case, though, most games are designed to take advantage of that technology.
Here are some factors to take into account when determining what sort of graphics card setup you need:
1) Game type – The more graphically demanding a game is, the more powerful video card(s) you will need in order to keep gameplay smooth. Games with lots of movement tend to be more demanding because of that: first-person shooters (FPSs) generally lead the way, followed by role-playing games (RPGs) – with real-time strategy (RTS) tending to be less intensive, and simulation games usually coming in last (though that depends on the sort of simulation – combat flight sims are more like FPS titles in this regard, due to lots of action and movement).
2) Screen resolution – Graphical needs are directly proportional to the number of pixels that the computer needs to calculate and draw, so running at a higher resolution will need a more powerful system. These days most folks are using flat-panel monitors, and they look the best when running at their native / maximum resolution. That is something to consider both when desiging a gaming computer and when selecting a monitor to go with it: you want to balance the two so that you don’t have to lower resolution when gaming, but you also don’t want to have such a small monitor that your computer’s power is wasted. In general, higher resolutions also require more onboard RAM per graphics processor in order to maintain good performance.
3) Quality settings – Games usually have a quality setting, or oftentimes several, that determines how much detail is displayed in the game and how complicated / accurate things like shadows are. The higher you put those settings the more work there is for your video card(s) to do. There are also universal settings called AA and AF: Anti-Aliasing and Anisotropic Filtering. Going into depth on what those are is outside of the scope of this article, but you can use the links on those words to look up more information. In short, they are post-processing effects that can be applied to 3D imagry in games to make jagged edges go away and overall make things look a little nicer – but when used they make further demands on graphics hardware.
As alluded to above, when you hit the maximum performance offered by a single GPU there is the option to go to two or more. The major graphics chip brands each have different ways of approaching this: nVidia refers to it as SLI, while ATI calls it Crossfire. Both manufacturers offer single-card solutions where two GPUs are present on one physical card, as well as multi-card solutions. These are most appropriate when your needs outpace what any single card can do, but sometimes it might also be more cost-effective to have two lesser cards instead of one extremely high-end card. In order to use these, though, you need to make sure that you select a motherboard and power supply that can handle them, as well as a case that can properly cool it all (more on that later).
As with CPUs, looking up benchmarks of current card options is one of the best ways to determine which will be most appropriate for your needs (based on the factors listed above). As mentioned previously, a video card is almost like a small self-contained computer in terms of the variety of components it contains – so there are individual specs you can look at like the clock speed of the GPU itself, the number of stream processors (similar to cores in a CPU) it has, the amount of onboard memory, the speed and type of that RAM, etc. However, just like with CPUs it is not always valid to compare cards on that level: differences in how the GPUs themselves are desgined, as well as drivers and other factors, mean that a benchmark-based comparison is much more useful and accurate than just comparing specifications. If you are purchasing a custom gaming computer online then talking to a sales representative is also a good resource, as they should be keeping up on the latest technologies and can help you determine what will fit your needs and budget the best.
The Rest of the Computer
Motherboard – Once you know what processor, how much memory (and what type), and what sort of video card setup you want to use then the motherboard should be pretty straightforward. It needs to have the proper type of CPU socket, enough RAM slots of the correct kind, and a sufficient number of PCI-Express slots for the video card(s). The chipset on the motherboard also needs to be able to support the correct multi-GPU standard if you are using more than one video card (currently SLI for nVidia cards and Crossfire for ATI), and it is a good idea to check with the motherboard manufacturer to make sure that the memory you want to use is on their qualified list.
Power Supply – This is what provides power at different voltage levels to the various components in a system, so it is important not to skimp here. You want something capable of running all of your hardware without approaching its maximum power rating (usually the number shown in the product name and on marketing materials for any given power supply), but you don’t want to go overboard either. A good rule of thumb is to have something where the idle power usage – when the system is just sitting not doing anything – is no less than 25% of the power supply’s rated maximum and the full load power usage is no more than 75% of the maximum. The range from 20 – 80% of maximum is usually where power supplies are most efficient, so keeping it in there will help your electricity bill later on. In addition, the capacitors and such in a power supply can degrade over time and with use – so you want to have plenty of headroom.
There are various websites with calculators for determining what level of power draw a system will have, and they are accurate to varying degrees. Here at Puget we provide and maintain a wattage calculator on our configure pages that shows both the estimated maximum power draw and the recommended power supply size as you customize a computer.
Besides the wattage and efficiency, you want to make sure you get enough connections to run all of the hardware in your system. With any decent power supply there will be plenty of Molex (standard 4-pin) and SATA power plugs for a gaming computer’s needs, so what you want to look for is the number of PCI-Express power leads. Just like checking the motherboard for PCI-E slots you need to ensure that the power supply has enough plugs to hook up all of your video cards. There are both 6-pin and 8-pin varieties, with different video cards needing different combinations, and in general 8-pin plugs can also serve as 6-pins – but not the other way around.
Chassis / Case – A computer’s case has several roles: to protect the components inside, to provide adequate airflow, to mount all the different parts needed to run the system, and in some cases to reduce noise or show off as well. When selecting a chassis you want to make sure that you get one large enough to hold the motherboard you’ve picked out, the video cards (some can be rather long), and whatever number of drives you want. Once those factors are taken care of you also need to consider the overall size and weight of the unit to ensure that it will fit well where you plan to put it, and make sure that there are enough fans present running at a sufficient speed to cool everything. Stock fans can usually be changed out in favor of quieter or more powerful versions, if need be, and other case modifications can be added to help reduce noise, add windows and lights, etc. Keep in mind that you will have to live with the system for as long as you plan to use it – so you want to strike the right balance of appearance and noise level in the finished product.
CPU Cooling – Similar to the fans in a case, this component is responsible for cooling and can affect overall noise levels. The stock fans included with CPUs are generally sufficient, but tend to be on the louder side and don’t do as good of a job at cooling as aftermarket products can. I say ‘can’ because not all 3rd party coolers are created equal: some are junk, while others are amazing. Because they change relatively often it is a good idea to research the options available for your specificly selected motherboard / CPU and then select a model that meets your cooling needs and desire for noise level.
Liquid-cooling is also an option for the CPU (and other components in a computer), but a comprehensive discussion of it is outside the scope of this article. In short, liquid-cooling will generally keep a few key components (CPU, GPU(s), and sometimes the motherboard chipset) running cooler than air alone could – but in trade they cost more, are more complicated to maintain, and can hamper future upgrades. They can also have an affect on noise level, since some fans (those on the CPU and video card) are no longer present. Not all fans can be removed, though, as some air cooling is still needed for the other internal components – and noise sources are added in the form of a pump and often additional fans to cool the liquid as it passes through a radiator. Because of this liquid-cooling is not usually the best choice for a quiet system, though in some cases it can be quieter than an extremely high-end computer would be on air alone. Where liquid-cooling really shines is in enabling better overclocking results, but again that is a topic for another time.
Hard Drives – The hard drive is where data is stored permenantly in a computer, and has a variety of characteristics that can affect how a system performs and what it is capable of. Thankfully it does not have a huge impact on gaming, at least not directly. A larger drive (in terms of capacity, measured in GB or TB – which are 1000GB) does mean you can hold more games at once, but even a relatively small drive can hold dozens easily. The speed of a drive, which is a function of a few different things, will affect how quickly Windows boots up, how fast games can launch, and the amount of time loading takes between levels – but once you are in the games itself there won’t be any impact on frame rates and such, assuming you have enough RAM. For this reason I don’t recommend spending a lot on a hard drive for a gaming computer; the money is generally better allocated to a faster CPU or video card(s).
Networking – For online gameplay, which is more popular with each passing day, the connection you are using to communicate with the outside world is very important. Most of this is dependent on your type of internet connection and the service provider you use, but the connection from your system to the modem for your service provider can make a difference too. For best performance you want a wired connection, as this is the lowest-latency choice (and latency, rather than bandwidth, is generally the factor governing online gaming performance; ping is a way of measuring latency commonly used in games). Most motherboards these days include at least one wired Ethernet port, so generally no additional hardware is necessary. There are specially designed network cards for gaming that can be employed, and in some cases they can provide a boost, but because of the relatively high cost they are usually a low-priority item for gaming computers.
If the location that your system will be in prevents using a wired connection then you will have to go wireless. There are two components that you will need to do this: a wireless adapter in the computer, and a router. To get the best performance look for units using the latest WiFi standards, and if possible select hardware from the same manufacturer for both devices. Compatibility should not be an issue even across brands, but setup may be easier that way.