Radeon HD 3870 X2
The Radeon HD3870 X2 was a temporary solution that should compete with older NVIDIA video cards until the appearance of the R700 chip and cards based on it. So, the new Radeon HD3870 X2 video card is positioned as a competitor to the GeForce 8800 Ultra.
The release of the ATI Radeon HD 3870 X2 returned AMD to the position of mid-2006, when the graphics division of the world's second largest supplier of x86 microprocessors was able to sell the fastest video card for $449.
In essence, the new product is nothing more than clock speeds GPU and memory is no different from two ATI Radeon HD 3870 working in CrossFire mode. Theoretically, the ATI Radeon HD 3870 X2 has impressive potential, allowing it to fight on equal terms with both the Nvidia GeForce 8800 GTX/Ultra, and with the GeForce 8800 GTS 512MB, however, predicting the performance of multiprocessor graphics systems is a thankless task; Only practical testing can give a concrete answer about their competitiveness in XNUMXD applications. Before we get to it, let's try to figure out how the new high-performance ATI video adapter works inside.
The task of combining two ATI RV670 graphics processors operating in CrossFire mode on one board is greatly simplified due to the presence of the Compositing Engine hardware unit in the core. In the first versions of CrossFire, this unit was external and was based on a separate Xilinx Spartan-3 FPGA; For the first time, the Compositing Engine was integrated into the graphics core in the ATI RV570, the chip that became the heart of the ATI Radeon X1950 Pro. The CrossFire logic diagram now looks like this:
In this case, everyone GPU uses its own PCI Express bus, which requires, firstly, the presence of two PCIe x16 slots on the motherboard, and secondly, support for CrossFire technology from the system logic set. AMD and Intel chipsets can boast of such support, but not Nvidia, which is not suitable for the ATI Radeon HD 3870 X2, positioned as a single graphics adapter. Obviously, it should work on any motherboard with any system logic set, and, of course, both graphics cores should be involved.
The logic of operation of two ATI Radeon HD 3870 X2 processors is no different from the logic of operation of two separate ATI Radeon HD 3870 combined in a CrossFire tandem.
Characteristics of ATI Radeon HD 3870 X2
| Name | Radeon HD 3870 X2 |
| Core | RV670 x2 |
| Process technology (µm) | 0.055 |
| Transistors (millions) | 666 |
| Core frequency | 825 |
| Memory operating frequency (DDR) | 900 (1800) |
| Bus and memory type | GDDR3 256 bit x2 |
| Bandwidth (Gb/s) | 115.2 (57.6 x2) |
| Unified shader units | 320 x2 |
| Unified shader unit frequency | 825 |
| TMU on conveyor | 16 x2 |
| ROP | 16 x2 |
| Shader Model | 4.1 |
| Fill Rate (Mpix/s) | 26400 |
| Fill Rate (Mtex/s) | 26400 |
| DirectX | 10.1 |
| Anti-Aliasing (Max) | MS-24x |
| Anisotropic Filtering (Max) | 16x |
| Memory Capacity | 512 х2 |
| Interface | PCI-E 2.0 |
| RAMDAC | 2 x 400 |
From a technical point of view, the new product was a success: the developers managed to fit two RV670 graphics chips with all their accompanying elements on one board, including memory chips and power stabilizers, as well as a rather large PCI Express switch chip, while fitting within the dimensions of the Nvidia GeForce 8800 GTX/Ultra. The relatively low level of heat dissipation of the RV670 and the support of ATI PowerPlay technology by this core made it possible to get by with a simple cooling system that does not even use heat pipes, which have long become a common attribute of high-performance graphics cards. On the one hand, the company really managed to create the most powerful single-board graphics adapter, capable of fighting on equal terms with the Nvidia GeForce 8800 GTX/Ultra and GeForce 8800 GTS 512MB, and in some cases even defeat them. But it was not possible to achieve 100% functionality of ATI's CrossFire technology.
Bioshock
