Computer Basics

How to Choose a Suitable Discrete Graphics Card

The core logic of choosing a discrete graphics card is to first determine its purpose, then match compatibility, and finally consider performance and budget. A graphics card not only determines the frame rate in games and the smoothness of design software but also needs to be physically compatible with the motherboard, power supply, and case. Blindly pursuing high performance can easily lead to "not fitting" or "not being able to power" the card, so it is necessary to carefully filter through the options step by step.

I. Step 1: Clarify the Purpose—Determine Whether a Discrete Graphics Card is Needed and What Level of Card is Required

A discrete graphics card is not "essential for all computers." First, assess the usage scenario to determine the need and avoid wasting budget:

Key Distinction: Gaming Cards vs Professional Cards

• Gaming Cards: Such as NVIDIA RTX 40 series, AMD RX 7000 series, optimised for gaming frame rates and ray tracing effects, offering high cost-effectiveness, suitable for gamers.

• Professional Cards: Such as NVIDIA Quadro series, AMD Radeon Pro series, specifically optimised for design software (e.g., CUDA acceleration in PR, Cycles rendering in Blender), but priced higher, with gaming performance not matching that of gaming cards at the same price point, suitable for professional designers.

II. Step 2: Confirm Hardware Compatibility—Avoid "Can't Install/Beyond the Power Supply Capacity"

Compatibility is a hard threshold and needs to be checked in three dimensions:

1. Interface Compatibility: Check the Motherboard's PCIe Version

• The mainstream interface for graphics cards is PCIe 4.0 x16, and new graphics cards (such as RTX 4070, RX 7800 XT) also support PCIe 5.0 x16;

• If an older motherboard only has a PCIe 3.0 x16 interface, the graphics card can still be used, but it will operate at a reduced speed (for example, a PCIe 4.0 graphics card in a 3.0 interface will have its bandwidth halved), which has a minimal impact on the performance of mid-to-low-end graphics cards, but can affect high-end graphics cards (such as RTX 4090) by approximately 10%-15%;

• There is no need to worry about "x16/x8": The mainstream motherboard graphics card slots are all x16, and even if they are reduced to x8, the performance difference in most scenarios is less than 5%.

2. Power Supply Compatibility: Check the Graphics Card's Power Consumption + Power Supply Capacity

• First, check the graphics card's "TDP (Thermal Design Power) consumption" (for example, RTX 4060 TDP 115W, RTX 4080 TDP 320W);

• The power supply capacity should have a 50-100W buffer: For example, if the graphics card has a TDP of 320W, the power supply should be at least 600W (it is recommended to choose 650W or above) to avoid overloading the power supply at full load;

• Pay attention to the power supply's "8Pin/16Pin power supply interface": Mid-to-high-end graphics cards (such as RTX 4070 and above) require independent power supply, so it is necessary to confirm whether the power supply has the corresponding interface (if not, a converter cable will be needed, but it is better to choose a power supply with a native interface).

3. Case Compatibility: Check the Graphics Card's Length and Thickness

• Measure the case's "maximum graphics card length" (for example, the case is marked as "supports graphics cards up to 330mm in length"), then check the actual length of the graphics card (for example, the RTX 4070 Ti is about 300mm in length) to ensure that the graphics card can fit into the case;

• For thick graphics cards (such as those with three fans), it is necessary to confirm the case's "maximum graphics card thickness" (for example, limited to 55mm) to avoid blocking other interfaces (such as hard drive interfaces).

III. Step 3: Understand the Core Parameters — Judge the Graphics Card's Performance

Parameters are the core of performance. There is no need to remember all the details, but focus on four key indicators:

1. GPU Model: The "ID Card" of Performance

• The model directly determines the performance level. Within the same brand, "the higher the number, the stronger the performance." It is better to focus on the model rather than the brand (for example, NVIDIA RTX 4080 > RTX 4070 > RTX 4060):

• NVIDIA Mainstream Models (2025): Entry-level (RTX 4050), Mid-range (RTX 4060 Ti/4070), High-end (RTX 4080/4090);

• AMD Mainstream Models (2025): Entry-level (RX 7600), Mid-range (RX 7700 XT/7800 XT), High-end (RX 7900 XT/7900 XTX).

2. Video Memory: Affects High-Resolution and Large-File Processing

Both the "capacity" and "type" of video memory are important and should not be overlooked:

• Capacity: For 1080P gaming, 6GB+ is required; for 2K gaming, 8GB+ is needed; for 4K gaming, 12GB+ is recommended; for professional design (such as 4K video editing, large 3D models), 16GB+ is necessary;

• Type:The type of video memory determines the bandwidth (speed). The priority order is: GDDR6X > GDDR6 > GDDR5. For example, an 8GB GDDR6X graphics card is more than three times faster than a 10GB GDDR5 graphics card, providing a better actual experience (avoid focusing only on capacity while ignoring the type).

3. Power Consumption (TDP): Related to Power Supply Selection

• The lower the TDP, the lower the power consumption and heat generation, making it suitable for laptops or small cases;

• The higher the TDP, the stronger the performance, but it requires a more powerful power supply and better cooling (for example, the RTX 4090 has a TDP of 450W, requiring a power supply of 850W or above).

4. Special Technologies: Key to Enhancing Experience

• Ray Tracing Technology: Supported by NVIDIA's RTX series and AMD's RX 7000 series, it can enhance the realism of game graphics. AAA game players should prioritise graphics cards that support ray tracing;

• Frame Generation Technology: NVIDIA's DLSS and AMD's FSR can increase the frame rate by 20%-50% without compromising image quality, which is essential for high-resolution gaming;

• Professional Acceleration: NVIDIA's CUDA cores and AMD's OpenCL can accelerate design software such as PR, AE, and Blender. Designers should prioritise graphics cards that support the corresponding technology.

VI. Pitfall Avoidance: Don't Fall into These Traps

• Focusing Only on Video Memory Capacity: For example, a 10GB GDDR5 graphics card is inferior to an 8GB GDDR6 graphics card. The type and bandwidth of video memory are more influential on speed than capacity;

• Ignoring Power Supply and Case: Purchasing a high-end graphics card but using a 500W power supply can lead to frequent crashes; if the graphics card is too long to fit into the case, it will have to be returned;

• Confusing Gaming Cards and Professional Cards: Using a professional card (such as Quadro) for gaming will not perform as well as a gaming card at the same price point; using a gaming card for professional design may result in poor software acceleration;

• Blindly Chasing the "Latest Model": The new model (such as RTX 4090 Super) may only offer a 10% improvement over the old model (RTX 4090), but the price is 20% higher, resulting in low cost-effectiveness. Unless the budget is unlimited, it is not recommended.

V. Summary of the Purchase Process

• Determine the Purpose: Decide whether a discrete graphics card is needed and whether it is for gaming or design.

• Check Compatibility: Confirm the motherboard's PCIe version, power supply capacity, and case dimensions.

• Select the Tier: Choose an entry-level, mid-range, or high-end model based on the budget.

• Pay Attention to Details: Prioritise models with larger video memory (matching the resolution) and those that support frame generation technology.