The graphics card is a complex component as it is able to process data itself, much like the processor does.
In the graphics card there is a graphics processing unit or GPU and a series of memory chips that allow to create and process a series of data independently from the main processor in the PC.
This processing unit is dedicated exclusively to the processing of data related to the graphics that will be eventually displayed on the screen.
Using this auxiliary processor takes that workload off the main computer processor, so it’s able to provide better graphics and higher performance.
However, depending on the usage you give your PC, you may not need any more graphics card than the one already integrated in your processor.
Integrated or dedicated?
Depending on the intended use of the PC, it could be enough to just use the graphics card that is integrated on some processors like the Core i3, Core i5, Core i7 from Intel or the A6, A8 and A10 from AMD.
For example, if the computer is to be used for office automation, or for general use with average performance, the graphics chip integrated on the processor should be enough to display the contents of your programs and videos on the screen.
This integrated graphics chips use part of the RAM memory available on the computer to process the graphics, so it shares resources with the main processor and could make the computer run slower.
If the PC is not going to perform demanding multimedia tasks, maybe you can do without a dedicated graphics card and use the one integrated in the processor.
On the other hand, if you want to play multimedia content in ultra high definition (4K UHD) or you’re setting up a computer for games, you’ll need to add a dedicated graphics card to improve the graphics performance of the PC and, also, it has to have enough power to process the latest ultra-realistic games, on a Full HD display and do so fluidly to avoid graphics jerking during action.
This dedicated cards have RAM memories and processors of their own, so the impact on performance is not noticeable.
Graphics cards for video games
Since there are different types of graphics cards aimed at different uses, we will give you some clues for you to choose the right one for your needs.
Most dedicated graphics cards can be included, with more or less performance, inside the category dedicated to processing multimedia content or games. But as it happens with other components of your PC, the power of the components makes a big difference.
If you plan on building a PC to play the latest games, we have bad news for you since you’ll have to fork out a lot of cash. In this kinds of setups, the graphics card is specially relevant and can account for more than 30% of the budget planned for the entire computer.
Although they share the same graphics chip, each manufacturer modifies their product to differentiate it.
In this sort of setups, you’ll also have to take into account the performance of the processor since, if it’s not powerful enough to manage data coming from the graphics processor, it will limit the performance of the graphics card, so you’ll be underusing it.
In addition to the power of the graphics processor offered by each graphics card model, you should also consider the amount of memory for each model and its speed since, even if two cards share the same graphics chip, each manufacturer can modify it and combine it with other components of higher or lower performance.
Some manufacturers can for example choose to add more video memory on the graphics card, but it can be a slower memory (GDDR3 instead of GDDR5).
In these cases it is advisable to always look for the model with the fastest memory, even if the amount is less. There is no point in storing lots of data to have ready when needed by the graphics chip, if you can’t convey them fast enough it will slow the card down.
Graphics cards for multimedia
Many of the integrated graphics chips in current processors already support even playing content in 4K. However, the best way to get maximum performance is to use a dedicated card tailored to the needs of your PC.
The need for a dedicated graphics card becomes more noticeable when you work on graphic or photo editing. In these two areas, having a sound graphics card makes a difference when processing the resulting files.
Professional graphics cards
In addition to graphics cards dedicated to multimedia entertainment or video games, there are other types of graphics cards aimed at professional 3D rendering tasks and other design generation functions.
These cards are not suitable for running games, neither are the more powerful gaming graphics cards good enough for this kind of tasks, nor are this cards good enough to execute the more demanding games, since they weren’t designed for those specific tasks.
If you are setting up a workstation that will be dedicated to rendering 3D textures, it is best to consult the technical recommendations of the programs you will use. This type of graphics cards are easily identifiable by their high prices.
Cooling system and noise
The graphics card, next to the computer processor, are the components that suffer the most from heat. So choosing a graphics card with a good cooling system will be an important factor for durability and user comfort.
The better the cooling system on the graphics card, the most heat it will be able to dissipate and the less the fans will have to work to keep it fresh, so it will directly affect on the noise generated by the computer.
Manufacturers offer different models integrating the same graphics processor with various alternative cooling systems. Choose the right one for your computer.
For example, if your PC is going to be used as a multimedia device, you can opt for passive cooling systems for your graphics card with oversized heatsinks that, given the lack of fans, do not generate any noise. This makes them ideal for Home Theater PCs (HTPC) or mini PCs.
Something similar happens with the different types of video connectors that graphics cards have in the back. Even if you find several models of different assemblers with the same graphics chip, each brand gives its cards different configurations of video connectors.
Choosing the appropriate connectors to connect your monitor to the resolution you need, will prevent having to use adapters when connecting different types of monitors to your computer.
Check the maximum resolution supported by each type of connector in the graphics card and decide if it’s the right one for your needs.
AGP, PCI, PCI-e and other expansion connectors
When choosing a graphics card you must keep in mind the type of connector to the motherboard you need.
Currently, all motherboards have PCI-e or PCI Express connectors for the graphics card, but if your motherboard is a little old, it is possible that the graphics card needs a PCI or AGP bus.
Beyond the physical difference between the different connectors formats of graphics cards, there is also a difference in performance.
As they have become more and more powerful, they have needed more bandwidth to carry all the information the current GPUs were able to process, so the connectors have evolved to meet this increase in transfer rate. Within the PCI-e or PCI-Express connector, which is currently the most used, you will find graphics cards with a PCI-Express 2.0 version and others with PCI-Express 3.0.
Both connectors are compatible and will work perfectly, but if your motherboard has support for PCI-Express 3.0 and you connect a PCI-Express 3.0 graphics card, its transfer rate will be higher and will allow greater bandwidth,so the graphics card will perform better than if you connect it to a motherboard with a PCI-Express 2.0 connector.
As mentioned at the beginning of this guide on how to choose your graphics card, graphics cards themselves are complete computation systems as they are able to manage and process themselves the calculations needed to produce the image you see on screen, without the computer processor intervening in that process or at least minimizing its intervention.
This feature is used by some applications to carry out their processes and optimize results.
Parallel processing is based on assigning a task to the graphics processor or GPU and then, the processor breaks that task among a number of sub-processors available, so that each performs a simple calculation and the results are joined together to complete the task and then the graphics processor returns the final result.
Given that these sub-processors can be counted by the thousands on each graphics card, you can imagine that solving this tasks with thousands of little processors working independently, is a lot faster that just one processor no matter how powerful it is.
In Nvidia models, this little processors receive the name of CUDA cores, while in AMD ATI they are called Stream processors.
Every architecture manages differently this sort of parallel processing, which is why 1000 Nvidia CUDA cores are not equivalent in power to 1000 ATI Stream processors. But within each architecture, you do notice the differences in the number of cores.
Memory interface or memory bus
Regardless of the amount of video memory or its type (GDDR3, GDDR4, GDDR5, etc…), the manufacturer will also specify the value of the memory interface. This parameter is expressed in bits and indicates the size of the communication interface between the graphics processor and memory. That is, the ability to carry more data from the video memory to the graphics processor. The higher the value, the greater the processing capacity the card has and, therefore, the better the performance.
Currently it is common to find cards with a memory interface of 128, 256, 384 and even 512 bits.
DirectX and OpenGL
DirectX is a programming interface developed by Microsoft which aims to simplify the task of interpreting instructions between different software components. If the graphics card supports the latest DirectX version it will be able to manage more effectively those instructions, so its performance with games or applications that use DirectX will be much higher.
On July 29, 2015 the latest version of DirectX 12 was officially launched, so most graphics cards of the market support DirectX 11, 11.1, 11.2 and 11.3 versions. OpenGL works similarly to DirectX. The latest version is OpenGL 4.4.
Overclocking consists in raising the frequency of the processor or the memories to make them work faster than their standard versions.
This is a common practice among experienced users, but for a few years, manufacturers also use it to give extra power to certain models of its catalog obtaining some Megahertz to the memories or processor frequencies. It is, to put it simply, a boosted version of a model that already exists.
Manufacturers indicate this feature in the model name so, for example, you may find a model Radeon R9 270X 2GB GDDR5 and another Radeon R9 270X OC 2GB GDDR5.
Both can appear to be the same to the naked eye, but when the moment comes, the OC version will always offer a slightly higher performance.
How many cards do you need?
If you are already clear that you will need a multicard setup, namely that you’re going to install multiple graphics cards interconnected to work together, keep in mind that the cards have to support that kind of connections, because they need a specific connector on the graphics card silicon board to connect both cards with a special dedicated cable, that bridges between the two cards, and that it’s named precisely that (bridge).
Normally, mid and high end cards support this sort of multi GPU configuration, but you must confirm with the technical specifications of the manufacturer.
On Nvidia models, this function is called SLI (Scalable Link Interface), while on ATI AMD models it is called Crossfire.
Alongside your graphics card supporting this multi GPU configuration, your motherboard has to be compatible too. So do not go buying cards left and right without first making sure both components allow it.
Beware energy consumption!
The energy consumption of the graphics card is also an important factor to consider.
Not just because it has been a trend to lower consumption lately, but because the power supply of your computer could not have the necessary watts to provide the power you need.
The graphics card receives part of that power through the PCI-e connector (or AGP) from the motherboard. Models from the mid/low and low range won’t need more power than that, but for those more powerful in the mid and high end, it will be necessary to complement this power with an additional 6-pin or 8-pin power cable (or even two, if the card is too powerful), also known as PCI-e power cable.
Therefore, this also must be taken into account when choosing your next graphics card, in the event that besides buying a new graphics card, you also need a more powerful power supply or the right connectors for it.
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