Radeon HD 7870
With the release of the Radeon HD 7800 line, AMD has completed the release of the new Southern Islands family to the market. Mid-range AMD solutions support all modern industry standards: GDDR5, PCI Express 3.0 and their future versions - DirectX 11.1. Since in terms of capabilities, the HD 7800 series completely repeats the features of the older HD 7900 series.
All of the company's new GPUs offer excellent features and performance not only in graphics processing, but also in non-graphical computing, including a mixture of different types of calculations. Also, the new GCN architecture offers a serious simplification of code optimization tasks, simplification of development and support, as well as stable and predictable performance and, in general, quite high efficiency.
The base block of the new architecture is the GCN block, and all GPUs of the Southern Islands series are assembled from them. The GCN computing unit is divided into four subsections, each of which works on its own instruction stream. Each GCN block has a dedicated 64 KB local data store for data exchange or local register stack expansion. Also, the block has a first-level cache memory with the ability to read and write and a full-fledged texture pipeline with sampling and filtering blocks. Each of the available GCN blocks is capable of scheduling and distributing instructions on its own, and one computing unit can execute up to 32 independent instruction streams.
Radeon HD 7870 Specifications
| Name | Radeon HD 7870 |
| Core | Pitcairn |
| Process technology (µm) | 0.028 |
| Core frequency | 1000 |
| Memory frequency (DDR) | 2400 (4800) |
| Bus and memory type | GDDR5 256-bit |
| Bandwidth (Gb/s) | 153.6 |
| Unified shader blocks | 1280 |
| Frequency of unified shader units | 1000 |
| TMU per conveyor | 80 |
| ROP | 32 |
| Shader Model | 5.0 |
| Fill Rate (Mpix/s) | 32000 |
| Fill Rate (Mtex/s) | 80000 |
| DirectX | 11.0 |
| Memory | 2048 |
| Interface | PCI-E 3.0 x16 |
Of course, since AMD again took the psychological threshold of 1000 MHz for the frequency of the GPU, the Radeon HD 7870 also received the “GHz Edition” addition to the name, indicating that this frequency was taken. After the HD 7770 GHz Edition, this is the second specially branded graphics card to have a standard frequency of at least 1 GHz.
The number of ROPs and memory controllers in the HD 7870 and HD 7850 is also the same as in the solutions of the youngest line. The number of ROP blocks was left quite high - 32 pieces for both models. The memory bus for boards based on Pitcairn has been cut down to 256-bit, it is assembled from four 64-bit channels. This is not bad for a solution of this level, although it is one and a half times less than in the top line, because the memory bus is traditionally cut down first. It's good that the use of fast GDDR5 memory gave a relatively high bandwidth of 153 GB / s.