What are the performance parameters of the graphics card? What does this mean? How to choose a graphics card?

First of all, we should understand the simple working principle of the graphics card: first, the data sent by the CPU will enter the graphics chip (that is, GPU or VPU) of the graphics card through AGP or PCI-E bus for processing. When the chip is processed, the related data will be transferred to the main memory for temporary storage. Then the digital image data will be sent to RA (Random Access Memory Digital Analog Converter), that is, random access memory digital analog converter, and converted into analog data required for computer display. Finally, RA cursed me to death, and AC sent the converted analog data to the display to become the image we saw. In this process, the data processing speed of graphics chip and the data transmission bandwidth of video memory will have obvious influence on the performance of graphics card.

Technical parameters and architecture analysis

First, the core architecture:

We often see the words "8× 1 architecture" and "4×2 architecture" in graphic articles. What do they mean? "8× 1 architecture" means that the graphics core of the graphics card has 8 pixel rendering pipelines, and each pipeline has 1 texture mapping units; "4×2 architecture" means that the graphics core of the graphics card has four pixel rendering pipelines, and each pipeline has two texture mapping units. In other words, in a clock cycle, the 8× 1 architecture can complete 8 pixel rendering and 8 texture maps; 4×2 architecture can complete 4 pixel rendering and 8 texture maps. Judging from the actual game effect, the performance of the two is very similar at the same working frequency, so they are often discussed together.

For example, when nVIDIA released GeForce FX 5800 Ultra, it did not describe its architecture in detail. Later, it was found that the statement that 8 pixels are processed in each cycle mentioned in the official document only refers to Z/stencil pixels, and its core architecture can be regarded as an improved version of the 4×2 architecture of GeForce4 Ti series and the later release of GeForce FX 5900 series. ATi's radium series 9700 and 9800 have a complete 8-pixel rendering pipeline. But the performance of these graphics cards is basically at the same level.

At present, the mainstream low-end graphics cards are basically 4× 1 architecture or 2×2 architecture, that is, only four texture maps can be completed per unit cycle. The higher-end products are 12× 1 architecture or even 16× 1 architecture.

Second, the core working frequency:

As the saying goes, "Diligence can make up for it". Although the high-specification architecture has inherent advantages, the low-specification core architecture can achieve the performance close to high-end products by increasing the working frequency.

For example, Radium Dragon 9500PRO adopts 8× 1 architecture, while Radeon 9600XT only has 4× 1 architecture. However, the core/memory operating frequency of Radiron 9500PRO with 0. 15 micron manufacturing process is 275MHz/540MHz, while Radeon 9600XT with 0. 13 micron manufacturing process reaches 500MHz/600MHz, and the core frequency is almost twice that of the former. Therefore, they can complete approximately the same number of pixel rendering and texture mapping in a unit time, so their performance is at the same level. Therefore, graphics card products with better overclocking performance by adopting more advanced manufacturing technology are often welcomed by players.

Third, memory bandwidth:

In large 3D games and other applications, a lot of data exchange is often needed between the graphics chip and the video memory of the graphics card. At this time, if the data transmission bandwidth of the video memory is too low, it will seriously restrict the smooth transmission of data, resulting in the graphics chip often in a state of "waiting for food", which is also a waste of chip performance. Therefore, when DIY players overclock the graphics card, they usually increase the core/video memory frequency together, so it is not easy to make the video memory bandwidth a bottleneck restricting the performance of the graphics card. The reason why the graphics card with 64-bit memory width is "despised" by players is precisely because the data transmission bandwidth of its memory has shrunk dramatically.

In addition to the contents mentioned above, the processing efficiency of graphics chips and the quality of drivers are also important factors affecting the performance of graphics cards.

Interpretation of graphics card performance

Through the above introduction, it should not be difficult for us to understand the actual performance of the graphics card from its technical parameters. For example, in the real game test, the speed of GeForce4 Ti 4200 with 4×2 architecture is better than the high-end graphics cards such as GeForce FX 5600, 5700, Laser Dragon 9600 and 9600PRO with 4× 1 architecture for many times. Only GeForce FX 5700Ultra and Radeon 9600XT can save a little face, but their core working frequency is almost twice that of GeForce4 Ti 4200, and their price is almost twice that of the latter. If it weren't for the inability to support DirectX 9 special effects, which limited the display space of GeForce4 Ti 4200, many mid-range graphics cards on the market would face a very embarrassing situation. No wonder 4200 can become a classic. And if we choose 4× 1/2×2 architecture graphics card products, we can also overclock them to achieve better performance.

Attached Table: Overview of pixel rendering pipeline specifications of mainstream DirectX 9 graphics cards

Pixel rendering pipeline nVIDIA ATi

AGP 8X graphics card PCI-E graphics card AGP 8X graphics card PCI-E graphics card

16 GeForce 6800Ultra

GeForce 6800GT GeForce 6800Ultra

GeForce 6800GT radium dragon X800 XT PE radium dragon X800 XT PE

12 geforce 6800 geforce 6800 radium dragon X800 professional edition radium dragon X800 professional edition

8× 1/4×2 GeForce 6800LE

GeForce FX 5900 series

GeForce FX 5800 series GeForce 6600 series

GeForce PCX 5900 radium dragon 9800 series

Radium dragon 9700 series

Radium Dragon 9800SE Game Edition

Radium Dragon 9500PRO Radium Dragon X700 Series

4× 1/2×2 GeForce FX 5700 series

GeForce FX 5600 series

GeForce FX 5500

GeForce FX 5200 series GeForce 6200

GeForce PCX 5750

GeForce PCX 5300 radium dragon 9800SE

Radium dragon 9500

Radium dragon 9600 series

Radium Dragon 9550 Radium Dragon X600 Series

Radium Dragon X300 Series