- RV770XT chip
- 512MB of GDDR5 memory
- 775MHz Core clock Turbo
- 1000MHz memory clock Turbo
- 256-bit memory interface
- 800 Stream Processors
- DirectX 10.1
- Pixel Shader 4.1
- Vertex Shader 4.1
- Geometry Tesselator
- Sonic Overclocking
- Dual Bios
- Dual Fan
- Dual Link DVI
- DisplayPort
- Smart Switch
- PowerPlay
- CrossfireX
- Avivo
- HDCP Capable
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| Brand Name | Palit |
| Part Number | A\E=4870S+0452 |
| Graphics Chip | RV770XT |
| Core clock | 750MHz/775 Turbo |
| Shader Clock | 750MHz/775 Turbo |
| SPs | 800 |
| Fabrication Process | 55 nm |
| Transistors | 965 Million |
| Memory clock | 1.8GHz/3.6GHz/ 1000/4GHz Turbo |
| Memory Interface | 256-bit |
| Memory bandwidth | 115.2GB/second/ 128GB/second Turbo |
| Memory Size | 512MB |
| ROPs | 16 |
| Texture Filtering Units | 80 |
| Texture Filtering Rate | 25 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 | 2x6-pin |
Palit chose to use the RV770XT based HD 4870 as the basis for this card. The HD 4870 is a 55 nanometer chip with over 965 million transistors, which is quite a jump up from the HD 3870 that preceded this card in ATI’s lineup, but not as large as the GeForce GTX 280 chip which has 1.4 Billion transistors. The HD 4870 has 800 Stream processors, which are broken down into 10 blocks of 32 SPs each capable of doing a 5D operation in a single clock.
ATI moved to GDDR5 memory with the HD 4870, the first video card on the market to support this new memory type. GDDR5 memory effectively doubles the bandwith at the same clock rate over GDDR3 memory used in previous video cards. The Palit 512MB Dual Sonic video card has a clock speed of 750MHz and a memory speed of 900MHz, which is the same as the reference card. When overclocking is enabled, the clock speed is bumped to 775MHz for the core and 1GHz for the memory.
Palit has implemented a Dual BIOS on their new card. The first BIOS is the standard BIOS and clock frequencies of 750MHz/900MHz core/memory. The second BIOS is enabled through flipping a switch. The clock speeds at that setting are 775MHz/1GHz. As I’ve already covered the performance of the standard 4870 clock speeds I will be using the overclocked BIOS throughout this review as that is one of the major selling points of this card.
ATI and S3 have not yet been joined by NVIDIA in supporting the Microsoft DirectX 10.1 standard. Only one game to date has been released with DX 10.1 support, Assassin’s Creed. The game developers took out DirectX 10.1 support with their first patch, meaning that there is no current game that requires DirectX 10.1. NVIDIA claims with some justification therefore that DX10.1 is not necessary. The next iteration of DirectX, DirectX 11 will require that any card that is compliant supports all of the features in DirectX 10.1, meaning that it is in fact relevant.
