Radeon HD 4000 series
| Release date | 2008 |
|---|---|
| Codename | Wekiva Makedon, Trojan[1], Spartan[2] |
| Cards | |
| Entry-level | RV710 |
| Mid-range | RV730, RV740 |
| High-end | Radeon HD 4850, HD 4870 |
| Enthusiast | Radeon HD 4850 X2, HD 4870 X2 |
| DirectX | 10.1, Shader Model 4.1 |
The Radeon R700 is the engineering codename for a Graphics Processing Unit series released by AMD Graphics Product Group, sold under the ATI brand. The foundation chip, codenamed RV770, was released on June 25, 2008. Further products including mainstream RV730 and entry-level RV710 products are expected to be released throughout 2008.
Architecture
Execution units
The RV770 extends the R600's architecture by increasing the stream processing units to 800 units (up from 320 units in the R600) that are grouped into 10 SIMD cores. The RV770 also has 40 texture units and 16 ROPs (raster operation units). [3]
Memory and internal buses
RV770 features a 256-bit memory controller and is the first GPU to support GDDR5 memory, which runs at 900 MHz giving an effective speed of 3600 MHz and memory bandwidth of up to 115 GB/s. The internal ring bus from the R520 and R600 has been replaced by the combination of a crossbar and an internal hub [3].
Multimedia features
The RV770 GPU see the implementation of UVD 2, offering full hardware MPEG-2, H.264/MPEG-4 AVC and VC-1 decoding and the support for dual video streams, the Advanced Video Processor (AVP) also saw an upgrade with DVD upscaling capability and dynamic contrast feature. The RV770 series GPU also supports xvYCC color space output and 7.1 surround sound output (LPCM, AC3, DTS) over HDMI. The RV770 GPU also supports Accelerated Video Transcoding (AVT) feature, which video transcoding is being assisted by the GPU through stream processing.
GPU interconnect enhancements
This generation of dual-GPU design retains the use a PCI Express bridge, PLX PEX 8647 with PCI Express 2.0 support, allowing two GPUs on the same PCI Express slot with doubled bandwidth over the past generation of product (Radeon HD 3870 X2). Current generation of dual-GPU design also features an interconnect for inter-GPU communications through the implementation of a "CrossFire X SidePort" on each GPU, giving extra 10 GiB/s inter-GPU bandwidth (5 GiB/s each direction). These two features increase total bandwidth for dual-GPU designs to 21.8 GiB/s.
Variants
Radeon HD 4800
The Radeon HD 4850 was announced on June 19, 2008 while the Radeon HD 4870 was announced on June 25, 2008. As of June 2008, these are the only two variants released. They are both based on the RV770 GPU, packing 956 million transistors and being produced on a 55 nm process. The Radeon HD 4850 currently uses GDDR3 memory, while the Radeon HD 4870 uses GDDR5 memory.
Dual GPU products using two RV770 GPUs are announced. One product named Radeon HD 4870 X2, featuring 2 GiB GDDR5 memory, was released on August 12, 2008, while another dual-GPU product, the Radeon HD 4850 X2, with GDDR3 memory and lower clock speeds, will be available later in 2008.
Future
The specifications for the architectures of the R800 and R900 families are "closed", with the specifications of the R1000 family being developed. [4]
New market strategy
- According to Phil Hester and Dave Orton, the firm has used a new strategy for the graphics market. Future GPU architectures will undergo small updates (presumably a die shrink at fabrication half-nodes, minor architectural changes, improvements to performance and power consumption, probably as well as implementation of newer API support if available) 6 months after first release, meaning the first GPU cores having only a 6-month product cycle. For mainstream and value segments, the product cycle will instead be 12 months without architectural alterations. The planned successor, presumably codenamed the Radeon R800 , will be targeted to launch on an even smaller fabrication process than the half-generation update (presumably codenamed R780) [5], while expecting that the Radeon R800 will be compatible with the next major version of DirectX API both of which are aimed at a 2009 launch.
- AMD is also shifting focus on releasing products. With the performance market in mind, the foundation GPU for the entire family of graphics products will be targeted towards the performance segment, enthusiast-market products are basically two foundation GPUs on a single PCB, while mainstream and entry-level products are deriatives and cut-down versions of the said GPU. This make a significant contrast towards the previous market strategy with developing the enthusiast-segment GPU in mind, while all other segments are basically cut-down versions of the GPU.
Chipset table
See also
References
- ^ ATI Radeon 4800 launch details: Meet (Terry) Makedon and Trojan (Horse)
- ^ R700 Spartan has 2GB of memory
- ^ a b Anand Lal Shimpi & Derek Wilson (June 25, 2008). "The Radeon HD 4870 & 4850: AMD Wins at $199 and $299". AnandTech.
- ^ The Inquirer report, retrieved September 12, 2007
- ^ Template:Ja icon PC Watch report
External links
