Ati Radeon HD 4800 Series is a classic. The first digit indicates the generation of the adapter. Behind the second is the family. The last two indicate a specific model. Initially, the cost of video cards of this generation began with a mark of 5,000 rubles. Now that the release of these devices has stopped, the secondary market can offer such devices at a price of 1000 rubles.
Core
The video processor received the name RV770. It includes over 900 million transistors. Of course, this is quite a lot, but not a record. However, an improved 55-nm process technology allowed them to lower the price of their production and temporarily outperform their competitors.
I must say that the frequencies of the ATI Radeon HD 4800 Series GPU are quite significantly reduced compared to the previous generation core. However, the increased power of texture processors should balance the lack of GPU frequencies.
Of particular note is the GDDR5 memory. Its application made it possible to raise the bar bandwidth without increasing its capacity. Of course, the price of GDDR5 is high, but this plays a minimal role, since the arrangement of all devices on the board is simplified.
The most problematic place for video cards with serial number 3 is texture processors. The increase in their number to 40 allowed to solve the main problem.
ALU Improvements
Any ATI Radeon HD 4800 Series graphics card is very dependent on the level of optimization of the shader code in the 3D program. However, the adapters of the series are equipped with eight hundred ALUs, and on each core of the processor there is a task manager to optimize the work in automatic mode. In the worst case, the code will be simultaneously processed in 160 ALU. If each computing unit is loaded to maximum, computing power will become equal to one teraflop. This figure is comparable to the ninth-generation NVIDIA flagship.
The end of ring architecture
Examining the ATI Radeon HD 4800 Series video card processor under a microscope, you can see that in general all the technical features of the previous generation of the core are preserved. However, now the architecture is not ring.
Memory controllers are integrated by bi-directional interfaces. Blocks that do not need quick access to instructions are located around the kernel. In addition, next to the processor is a switch, it connects devices for which bandwidth is not critical. If the efficiency of the core elements of the previous generation could reach 85%, then the improvements made it possible to bring it to a practical maximum. ATI experts say that computing units have become 40% more efficient.
Dispatch processor
The task manager can be called the key device of any graphics processor. His job is to efficiently allocate resources. In this case, all parts of the kernel should be loaded the same way. If this condition is met, performance will be maximized.
In the ATI Radeon HD 4800 Series processor, the number of blocks for storing and processing code has increased. The number of SIMD arrays has also become large. Due to this, each array now works not in isolation, if necessary, data exchange is possible. In addition, the task manager algorithms have undergone optimization.
Texture blocks
In the third generation of video adapters, there were only 16 texture units, which is absolutely not enough for most 3D applications. Moreover, for each TMU there was only one filtering unit. This became especially noticeable when anisotropic filtering was turned on , and it is used everywhere.
The developers took into account the experience of previous errors. Now in each TMU module there are 16 blocks that perform texture sampling, and 4 filtering and addressing blocks. Together with the increased throughput of TMU, the performance of this element increased by 2.5 times.
The modules, as in the old generation video adapters, are combined by 4. However, due to optimization, the number of transistors has decreased here.
Cache
The ATI Radeon HD 4800 Series graphics card, whose characteristics have grown significantly compared to the younger adapters, received a new cache system. Now data exchange with the cache of the first level occurs at a speed of about 480 Gb / s, of the second - more than 380 Gb / s. In addition, all SIMD cores now have their own memory, which allows you to operate simultaneously with a large amount of information.
New opportunities
In addition to the main innovations, it will not be superfluous to note smaller ones. All HD 4800 video cards have a Realtek controller in their kit, which allows you to work simultaneously with eight channels. At the same time, the maximum output bitrate is just over 6 Mb / s. The upper bar of sampling frequencies is at 192 kHz.
Advanced features are very important for those who are going to connect a multimedia system to the computer. The ATI Radeon HD 4800 series, reviews of which are already flattering to the manufacturer, because of the features described above, has received in its army of fans also users who are not interested in computer games.
The built-in universal video decoder not only easily copes with playing high-definition video, but can also simultaneously display it on two different monitors. At the same time, different signals can be output to each output device.