- 55 nanometer
- 956 million transistors
- RV770 chip
- 625MHz core clock
- 1986MHz memory clock
- GDDR3 Memory
- 256-bit memory interface
- 63.6GB/second memory bandwidth
- 16 ROPS
- 800 Stream Processors
- 32 Texture units
- DirectX 10.1
- Pixel Shader 4.1
- Vertex Shader 4.1
- Unified Video Decoder
- AVIVO
- Quad Heatpipe cooling solution
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| Brand Name | Gigabyte |
| Part Number | R4850 512M |
| Graphics Chip | RV 770 Pro |
| Core clock | 625MHz |
| Shader Clock | 625MHz |
| SPs | 800 |
| Fabrication Process | 55 nm |
| Transistors | 956 Million |
| Memory cloick | 1.986GHz effective |
| Memory Interface | 256-bit |
| Memory bandwidth | 63.6GB/second |
| Memory Size | 512MB |
| ROPs | 16 |
| Texture Filtering Units | 32 |
| Texture Filtering Rate | 20 Gigatexels/second |
| HDCP Support | Yes |
| HDMI Support | Yes (via adapter) |
| Connectors | 2x Dual-Link DVI, TV-Out |
| RAMDACs | 400MHz |
| Bus | PCI Express 2.0 |
| Form Factor | Dual Slot |
| Power Connectors | 1x 6-pin |
The MSI Radeon 4850 card is based upon ATI’s RV770 Pro chip which is built on 55 nanometer process from TSMC and has 956 million transistors. The chip is the same as the RV770XT chip found on the HD 4870 cards with the exception of having a slower clock speed, 625MHz compared to the 750MHz on the HD 4870 cards and the use of GDDR3 memory instead of GDDR5 on the HD 4870 card.
The RV770 Pro chip has 160 execution units each of which is capable of running a 5D operation in a single clock. This leads to ATI’s claims of 800 Stream Processors on the HD 4850 card and the card is capable of 1 TeraFLOP of computing performance. The HD 4850 has 32 texture units and 32 ROPs (Outputted Pixels) meaning that it has a pixel fill rate of 10 Gigapixels a second and a texel fill rate of 20 Gigatexels a second.
Microsoft has begun talking about the next iteration of their graphics API (Application Programming Interface), DirectX 11 at Siggraph and nVision, NVIDIA’s marketing term for their graphics related conference. The current state-of-the art is DirectX 10.1 which ATI was the first graphics card company to support with the HD 3870 launch last year. The HD 4850 and 4870 both support this API which adds support for Global Illumination and more features to the Anti-aliasing modes of video cards.
The 4850 has a 256-bit memory interface with GDDR3 memory clocked at 1986MHz. This gives an effective memory bandwidth of 63.6GB/second. The use of GDDR5 memory on the bigger brother 4870 card is gives that card 115.2GB/second memory bandwidth. One thing that the card has going for it that the earlier video cards of this generation is the lack of a ring bus that was present on the HD 3xxx series. This card is targeted to the under $200 video card market and that market is using the 256-bit memory bus.
