How to Choose a Graphics Card for a Custom PC: Performance, Features, and Compatibility

A graphics card is a component used for processing images and is designed to display visuals on a computer beautifully and smoothly.

This part is not absolutely necessary if the CPU has a built-in GPU function.

However, for uses that require high graphics performance, such as 3D games or 3D modeling, a graphics card is essential.

If a graphics card that does not meet the graphics performance required by 3D games is installed, the screen may stutter or become sluggish, making smooth gameplay impossible.

Therefore, this article will explain the knowledge, functions, performance, and compatibility of graphics cards necessary for building a custom PC, as well as how to choose one from these perspectives.

Basic knowledge, roles, performance, and compatibility for other PC parts are also explained, so please refer to them.

≫ Related article: PC Parts List and Explanation of Each PC Part [A Must-Read for Custom PC Beginners]

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What is the Role of a Graphics Card?

A graphics card is a component responsible for image processing and video output.

It is necessary for displaying the results of various app processes on the display and for handling complex 3D graphics processing.

It is called by various names, such as GPU (Graphics Processing Unit), graphics card, video card, or “gurabo” in Japanese.

While the CPU handles the overall processing of the computer, the GPU handles graphics-related processing.

The CPU, memory, and storage are essential parts, but the graphics card is not always essential.

However, this is only if the CPU has a built-in GPU function.

However, a CPU’s built-in GPU only provides the minimum graphics performance needed to output video to a display.

Therefore, for uses that require higher graphics performance, a graphics card is installed.

For example, 3D games, 3D modeling, and 3DCG require high graphics performance.

Also, for video editing encoding or AI learning, the high computational power of a graphics card can process tasks much faster than a CPU.

Using a graphics card’s computational resources for non-graphics processing is called GPGPU.

Basic Knowledge of Graphics Cards

Before explaining how to choose a graphics card, this section covers the main manufacturers, how to read model numbers, and performance guidelines for different uses.

Let’s explain these points in detail.

The Three Major Graphics Card Manufacturers: “NVIDIA”, “AMD”, and “Intel”

There are three main manufacturers of graphics cards for PCs:

• NVIDIA
• AMD
• Intel

Among these, the NVIDIA GeForce series is the most popular, and most gamers use this series.

The next most popular is the AMD Radeon series.

Intel, originally a leader in CPUs, entered the graphics card market in September 2022.

In fact, this is a return after 24 years. While Intel has offered integrated GPUs, dedicated graphics cards are a different field, so development is almost from scratch.

As a result, the recently released Intel Arc series has lower performance and higher prices compared to the other two manufacturers, so there are high expectations for future improvements.

How to Read Graphics Card Model Numbers (Understanding Performance)

Graphics cards have model numbers, and by looking at these, you can roughly understand their performance.

Although each company has various series, this explanation will focus on the commonly used NVIDIA GeForce and AMD Radeon as examples.

Since the manufacturers were already mentioned, let’s explain the series here.

Series

A series refers to a specific product line from a manufacturer.

For example, NVIDIA has the “GeForce” series, and AMD has the “Radeon” series.

These are for consumers, and when building a custom PC, most people choose from these brands.

Let’s list them with explanations.

The most popular is the NVIDIA GeForce series, followed by the AMD Radeon series.

Other series are more expensive, and even for video editing or engineering, GeForce is usually sufficient for consumers.

Class

Class refers to specific technologies or series.

For example, GeForce’s “RTX” features real-time ray tracing for better visuals and new AI-oriented cores called tensor cores.

When major new technologies are introduced, the class name often changes.

Generation

The generation of a graphics card shows how new it is.

With each new generation, performance improves, new technologies are adopted, and energy efficiency gets better.

A new graphics card usually comes out every 2-3 years, and the number increases each time, so knowing the generation helps estimate when it was released.

For custom PCs, most people use the latest generation unless there is a special reason, but sometimes choose the previous generation for price reasons.

Performance

Performance indicates the level within the same series, class, and generation.

For example, the following are listed from highest to lowest performance:

• RTX 4090
• RTX 4080
• RTX 4070
• RTX 4060

However, if the generations are different, the numbers do not always match the performance order.

For example, RTX 4070 and RTX 3080:

The RTX 4070 is newer (“40”), but the RTX 3080 (“80”) has a higher performance number.

However, checking the benchmark scores shows:

So, while the “performance” number is higher for RTX 3080, the newer generation RTX 4070 can outperform it.

Therefore, pay attention to both “performance” and “generation” when choosing.

Suffix

Some graphics cards have letters at the end of the model number, indicating special features or characteristics.

For example, with NVIDIA GeForce RTX 4060, here are some suffixes:

By the way, even if Ti or SUPER models have improved performance, upgrading to the next performance level (e.g., RTX 4080) usually offers higher performance.

This is not always the case, and sometimes Ti or SUPER models are about the same or slightly better, depending on the generation.

Still, know that the performance improvement with Ti or SUPER is within that range.

Here is a rough classification of recent mainstream graphics cards (including CPUs with integrated GPUs):

Low-end means no dedicated graphics card, just a CPU with an integrated GPU.

This provides the minimum graphics performance for video output and can handle 2D games and browser games.

For mid-range, cards like RTX 4050 or RTX 3060 offer enough graphics performance for a wide range of games, making them a good choice for gaming PCs.

They are also suitable for 3DCG and modeling, and the typical price range is about 150,000 to 200,000 yen, making them cost-effective.

Mid-high class is for those who want to record game streams, play at high quality and FPS, and do heavy video editing or use multiple demanding applications at once.

High-end mid-range cards can handle this, but for even better quality and efficiency, professionals and semi-professionals may prefer this class.

High-end class is for the heaviest tasks in each field.

For example, playing very demanding 3D games at the highest quality and 4K, or applying heavy effects to entire videos in editing, this class is recommended for those who want stress-free speed even for very heavy tasks.

Performance Guidelines by Graphics Card (by Usage)

Now that you understand the approximate performance from the model number, let’s explain by usage.

The most important thing is to choose a graphics card with enough performance for your intended use.

Therefore, let’s look at the minimum graphics performance needed for each use.

There is a wide range from low-end to high-end, but even for the same use, the required performance changes depending on what you want to do.

For example, for gaming, the performance needed changes depending on whether you want to play in FHD, 4K, or with high-quality settings.

For more details, see the links in the “Usage” column of the table, which explain performance guidelines for each level.

No Graphics Card Needed (CPU with Integrated GPU)

A graphics card is not a required part, so a PC will work without one.

However, the following conditions apply:

• The CPU must have an integrated GPU (graphics processing unit)
• High graphics performance is not needed for 3D games, 3DCG, or modeling

CPUs with integrated GPUs can handle basic video output and light graphics tasks without a graphics card.

For everyday use such as document creation, web browsing, or watching videos, the CPU’s integrated GPU is enough.

On the other hand, for uses that require high graphics performance, such as 3D games or 3DCG/modeling, the integrated GPU is often insufficient, so a dedicated graphics card is needed.

Therefore, it is important to choose a graphics card based on your needs, and not all users require one.

High Graphics Performance is Essential for Certain Uses [3D Games, etc.]

Using a CPU with an integrated GPU means the PC will work without a graphics card.

However, for uses that require high graphics performance, such as 3D games, 3DCG, or 3D modeling, a graphics card is almost essential.

For browser games or 2D games, the CPU’s integrated GPU may be enough, but for 3D games, the graphics processing increases greatly, and the integrated GPU is usually not enough.

The increased graphics processing for 3D games includes:

• Modeling each object in 3D space and applying textures (surface images)
• Processing light sources in 3D space (direction, intensity, color, etc.)
• Real-time shadow processing based on light sources (shadows change as lights or objects move)
• Movement of grass and trees in fields
• Reflections on water or glass surfaces
• Physics calculations for object movement, falling, collisions, explosions, etc.
• Rendering 3D objects onto a 2D screen
• Redrawing when the player’s viewpoint (camera) moves

These are just some examples, but compared to 2D, the amount of processing increases dramatically, so much higher graphics performance is needed.

In addition to these advanced graphics processes, to play games comfortably, the image needs to update about 60 times per second (60 FPS).

In other words, outputting 3D graphics increases the processing load so much that a low-performance integrated GPU cannot keep up.

If the GPU cannot keep up, the game may not run at all, or if it does, it may only run at about 20 FPS (20 frames per second), resulting in choppy visuals.

This leads to poor gameplay and frustration.

Therefore, for 3D graphics uses, a graphics card is essential, and its performance is the most important factor.

3D games are the most popular use for 3D graphics, and there are measurements of required specs and average FPS by graphics card, so please refer to them.

≫ Related article (Pasolog): Recommended Specs and PCs for Gaming [12 Games/30+ PCs Reviewed]

≫ Related article (Pasolog): Gaming PC Graphics Card Performance and Benchmark Results

Using GPGPU for Non-Graphics Tasks [Video Editing/AI, etc.]

GPGPU (General-Purpose computing on Graphics Processing Units) is a technology that uses the GPU for general-purpose calculations beyond graphics processing.

GPUs were mainly used for fast graphics rendering in games and 3D applications, but GPGPU extends this to a wider range of computational tasks.

In terms of raw computational power, graphics cards have higher processing power than CPUs.

GPGPU leverages this high computational power for tasks other than graphics, such as:

• Video editing encoding
• AI learning, machine learning, deep learning
• Big data processing and analysis
• Scientific calculations and simulations

Video encoding can be done in less than half the time compared to a CPU, and AI learning can be 20-50 times faster.

For more details on use cases, performance differences, and processing speed, see the following:

≫ Related article: What is GPGPU? Technology to Use High Parallel Processing Power Beyond Graphics

How to Choose a Graphics Card for a Custom PC [Performance]

This section explains how to choose a graphics card focusing on performance and features.

The main indicators of graphics card processing performance are the number of cores and clock frequency.

Graphics cards have various features that affect performance, but basically, performance is determined by the number of cores and clock frequency.

However, since both factors affect performance, you cannot simply compare graphics cards based on these alone.

It is good to know about cores and clock frequency, but when comparing graphics cards, it is best to refer to benchmark site scores.

Custom PC Tools also summarize statistical data on popular rankings, price ranges, and specifications based on user selections.

≫ Related article: Popular Graphics Card Rankings and Selection Rates by Specification [Statistical Data]

Number of Cores

The number of cores refers to how many units can process graphics tasks simultaneously. The more cores, the more tasks can be handled at once.

GPU cores are mainly used for image rendering and visual content processing.

They are well-suited for parallel computation, handling many small tasks at the same time, making them ideal for games, graphics rendering, video editing, machine learning, and data analysis.

However, the concept of cores differs by manufacturer, so you cannot simply compare core counts between brands.

Also, CPUs usually have about 10-20 cores, but NVIDIA GPUs have 2,000-15,000 cores, which is a huge difference.

GPUs have lower clock frequencies, but thousands of cores can process tasks simultaneously, enabling tremendous calculations.

Since the concept and characteristics of cores are different, you cannot simply compare them, but this gives an idea of the GPU’s computational power.

Clock Frequency

Clock frequency indicates the GPU’s processing speed.

More precisely, it is the number of signals sent to synchronize the timing of multiple electronic circuits inside the computer.

In simpler terms, the more signals per second, the shorter the interval for sending and receiving data, resulting in faster processing.

So, it means processing speed.

The number of signals per second is measured in Hz (hertz).

For example, 2.3GHz means 2.3 billion signals per second.

Comparing GPU Performance: Benchmark Sites

To compare GPUs, use benchmark sites.

A benchmark is a test that measures processing speed and efficiency, allowing you to see performance differences between GPUs.

A commonly used benchmark site is ‘PassMark‘.

Although GPU performance is determined by “number of cores” and “clock frequency,” comparing just these two does not give a clear answer.

For example, comparing:

• A GPU with many cores and high clock frequency
• A GPU with fewer cores and lower clock frequency

If one factor is the same, you can compare the other, but this is rare. Also, even if the numbers are the same, performance may differ between manufacturers.

In such cases, benchmark sites allow you to compare GPU performance using score numbers.

Types and Number of Video Output Ports

Graphics cards have video output ports for outputting processed images.

Most recent graphics cards have multiple HDMI and DisplayPort outputs.

Other ports like DVI and VGA (D-Sub) are rarely included on modern graphics cards.

Typically, there are about four ports, such as three DisplayPorts and one HDMI.

See What are Video Output Ports? for explanations of port types and features.

Especially if you want a multi-monitor setup with two or more screens, check in advance that the number and types of ports match your monitors.

Also, if you use the video output ports on the motherboard, you won’t be using the graphics card’s performance, so 3D games may stutter.

Therefore, be careful about where you connect your monitor when setting up your PC.

How to Choose a Graphics Card for a Custom PC [Compatibility / Important]

This section explains how to choose a graphics card focusing on compatibility.

If you choose a graphics card that is not compatible, it may not fit on the motherboard, so be sure to check.

Let’s explain these points in detail.

Does the CPU Require a Graphics Card?

If the CPU does not have a built-in GPU, a graphics card is required.

If the CPU lacks a built-in GPU and you don’t install a graphics card, you won’t be able to output video to the monitor, so be careful.

To check if the CPU has a built-in GPU, there are two ways:

• Check the specifications on the product page
• Check the product model number

Check the Product Page Specifications

Go to the product page using the CPU model number and check the graphics section.

For Intel CPUs, look for “GPU Specifications”; for AMD, look for “Graphics Capabilities”.

If these sections exist, the CPU has an integrated GPU.

If not, it does not, so install a graphics card.

Check the Product Model Number

You can also tell from the CPU model number.

Some model numbers have a letter at the end, which indicates whether there is an integrated GPU.

For Intel Core i series, any suffix except “F” means integrated GPU; for AMD Ryzen, a “G” at the end means integrated GPU.

However, for recent AMD Ryzen generations, some models without “G” also have integrated GPUs, so it’s not always clear.

Therefore, it’s best to check the product page.

Graphics Card Size (Length)

When choosing a graphics card, make sure it fits inside the PC case.

If the graphics card is too long, it won’t fit in the case and can’t be assembled. If it’s a tight fit, it may touch the case, causing vibration, noise, or even damage.

So, leave at least 1cm of space.

Also, depending on the PC case, the maximum graphics card length may be shorter if there is an HDD bracket or if a water-cooled CPU cooler is installed at the front.

These conditions are usually listed in the case specifications, so check both the graphics card length and the case’s supported length.

Graphics Card and PCI Express Slot Interface

Check the shape and version of the PCI Express slot on the graphics card and motherboard.

First, regarding shape, PCI Express comes in x16, x8, x4, and x1 sizes, with different slot lengths.

It is usually written as “PCI Express x16” or “PCIe x16”.

Shorter PCI Express cards can be inserted into longer slots. For example, x8, x4, or x1 cards can be inserted into an x16 slot.

Most recent graphics cards support PCI Express x16, so check that the motherboard has a PCI Express x16 slot.

PCI Express versions include 4.0, 5.0, 6.0, etc.

These are backward compatible, so you can use older graphics cards in newer slots.

However, for maximum performance, it’s best to match the graphics card and motherboard PCI Express versions.

Types and Number of PCI Express Connectors on the Power Supply for Auxiliary Power

To run a graphics card, in addition to power from the PCI Express slot, auxiliary power is needed.

This auxiliary power comes from the power supply’s PCI Express connectors (8-pin/6-pin) or 12VHPWR, so choose a power supply that matches the required connector type and number for the graphics card.

There are two main types of auxiliary power connectors for graphics cards:

• 12VHPWR
• 8-pin

There is also a 6-pin, but it’s rarely used in recent graphics cards.

The required power varies by product, so the type and number of connectors needed also changes.

12VHPWR is for recent high-performance, high-power graphics cards and can supply up to 600W, so one is enough.

However, 8-pin connectors supply up to 150W each, so some graphics cards require two or three.

If there are not enough connectors, the graphics card may be unstable or not start at all, so check the types and numbers of connectors on both the graphics card and power supply.

For more on auxiliary power types and related PC part selection, see:

≫ Related article: What is Graphics Card Auxiliary Power? 12VHPWR/8, 6-pin and Connection Tips!

Slot Size (Number of Occupied Slots)

Slot size refers to how many expansion slots the graphics card uses when installed on the motherboard.

High-performance graphics cards often have large heatsinks and fans for better cooling, so they usually use two or more slots.

If you only use the expansion slots for the graphics card, this is not a problem.

However, if you also want to install a Wi-Fi/Bluetooth card or capture card, the slots may interfere and not fit.

Therefore, check the graphics card’s slot size and the position of the PCI Express slots on the motherboard to ensure other expansion cards can also be installed.

Additional Knowledge about Graphics Cards

This section explains useful knowledge about graphics cards, though not as important as performance or compatibility.

Let’s explain these points in detail.

Difference between Graphics Card and GPU

“Graphics card” and “GPU” are often used interchangeably to mean the part that handles graphics processing, but strictly speaking, they are different.

GPU (Graphics Processing Unit) refers to the chip that processes graphics.

A graphics card is the board that includes the GPU, as well as memory, power circuits, heatsinks, fans, and output interfaces.

NVIDIA and AMD design the GPU chip and supply it to parts manufacturers, who then add memory, power circuits, heatsinks, fans, and output interfaces to sell it as a graphics card.

However, most people understand either term, so strict distinction is not usually necessary.

Relationship between Graphics Cards and AI

In AI and machine learning, huge amounts of data need to be processed quickly.

GPUs were originally good at image processing, but their high computational power is also suitable for complex AI calculations.

Especially in deep learning, which uses multi-layer neural networks, the GPU’s parallel processing ability is a big advantage.

Recently, image generation AI has also appeared, and running it locally requires high graphics performance.

Choosing a high-performance graphics card with many cores can shorten AI training time and enable more complex models.

Also, running image generation AI locally can reduce generation time.

When choosing a graphics card, consider the specs needed for AI use.

Summary: At Least Learn to Estimate Performance from the Graphics Card Model Number!

A graphics card is a component responsible for image processing and video output, and its performance affects the comfort of gaming and other tasks.

If you choose a graphics card with inadequate performance for your needs, work may not be comfortable or may not run at all.

Therefore, choose a graphics card with enough performance for your intended use.

Here is a summary of how to choose a graphics card.

A graphics card is not necessary if the CPU has a built-in GPU function.

However, for uses that require high graphics processing, such as 3D games, 3DCG, or 3D modeling, consider it essential.

When assembling, be careful about the graphics card length, PCIe slot interface, and the type and number of PCIe connectors on the power supply.

Also, in terms of performance, decide your intended use, research the required performance, and choose according to your budget.

Basic knowledge, roles, performance, and compatibility for other PC parts are also explained, so please refer to them.

≫ Related article: PC Parts List and Explanation of Each PC Part [A Must-Read for Custom PC Beginners]

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PC Parts Estimation & Compatibility Check Tool

Automatically checks each component you need when selecting parts for a custom-built PC—perfect for beginners.